• 한국기계가공학회지
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• 제8권4호
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• pp.1-6
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• 2009

Air drying technology was developed as an equipment for reducing of moisture content from wastewater treatment and waterworks sludge cake and reproducing it by reusable matter. Advantage of cyclone type pneumatic dehydrator is simple and excellent drying performance. The air drying equipment was composed to the air ejector which made high-speed fluid field, and cyclone which made circling fluid field. Dewatered cake was crushed at the high-speed zone as first step, and formed with dried powder of sphere shape by the collision between particles at the circling fluid zone. In this study, a CFD analysis has been performed to predict air-sludge particles flow in cyclone and ejector of pneumatic dehydrator. The computational results showed typical Rankine vortex structure which was frequently found in swirling flow phenomena. And the conical type wedge in lower part of a cyclone prevented accumulation of the sludge particles in the cyclone. Therefore, this technology was effective in drying of dehydrated cake of waterworks sludge.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권1호
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• pp.21-26
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• 2016

Canine cataract is developed with aging and can cause the blindness or surgical treatment if not treated timely. The first observation must be made by pet owners but they do not have proper equipment and knowledge to see the abnormalities. In this paper, we propose an intelligent image processing method to extract canine cataract suspicious object from non-professional equipment such as ordinary digital camera and cellular phone photographs so that even casual owners of pet dog can make a pre-diagnosis of such a surgery-needed disease as soon as possible. The experiment shows that the proposed method is successful in most cases except the dog has similar colored hair to the color of cataract.

• 한국대기환경학회지
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• 제29권4호
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• pp.486-503
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• 2013

This paper has comprehensively reviewed fine dust control technology from emission sources. Owing to the stringent national regulation, domestic industries have made consistent efforts to develop the high efficiency facilities since 1960s. In these days, harmful particulate pollutants including dioxins and PAHs as well as $PM_{2.5}$ are also of critical interests in government and civic groups. In addition, simultaneous treatment of gas and particles is being widely studied. It is believed that hybrid facilities which integrate a few advanced equipment may meet the atmospheric guidelines.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.108-109
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• 1998

As the need of enhanced medical treatment grows up, Purchasing step which include medical engineer's opinion has to be required. On this procedure, Medical Engineer Departments has used $\ulcorner$comparision chart$\lrcorner$. In this paper, How to compose and utilize comparison chart for purchasing of medical equipment by medical engineer in the hospital. It is made through the technical and objective investigation. From these points, We think that it can be available for proper installation and improved maintenance.

• 상하수도학회지
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• 제23권4호
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• pp.499-505
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• 2009

Many other countries have investigated the residual sludge treatment process to save the existing water resource and produce the high suspended solid concentration sludge. There are various methods for concentrating residual sludge, but the membrane system has received the most interest for its efficiency. The objective of this study was to evaluate the application of membrane filtration system for the residual sludge treatment. The experiment equipment was composed of Lab scale Crossflow tubular membrane filtration system. Generally, crossflow operation mode demands high electric cost mainly for the pump energy. So to cut off electric cost, very low Crossflow velocity was used in this experiment. Results confirmed that suspended solid concentration of residual sludge could be concentrated to 57,000mg/L in low Crossflow velocity tubular membrane system,. This concentration can be directly injected into the dehydrator. Based on the results, we know that the Crossflow tubular membrane system should be replaced conventional residual sludge treatment system.

• 상하수도학회지
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• 제33권4호
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• pp.311-319
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• 2019

The purpose of this study was to analyze water treatment characteristics, including the efficiency of removing algae from water purification plants, by installing a demonstration facility for decontamination of algae, including natural algae remover injection equipment, in the water purification plant. Jar-test showed that the optimum injection of natural decontaminant was 20 mg/L. Of the water contaminant treatment efficiency of the intake and water purification plants, Chl-a averaged 74.0% elimination efficiency from $5.0mg/m^3$ to $1.3mg/m^3$ and the maximum treatment efficiency was 91.5% removal efficiency when the inflow concentration of Chl-a was $11.8mg/m^3$. In addition, 51.2% and 47.1% of the taste and odor indicator items, geosmin and 2-MIB, resulted from the overgrowth and decaying of algae, respectively, to identify toxic substances and odor reduction effects. In addition, elimination efficiencies of SS and Turbidity materials were higher than 70.0%. In the injection of natural algae remover, no effects such as sudden changes in water quality due to secondary reactions were found, and appropriate levels were maintained under water treatment conditions.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.777-782
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• 2001

In this study, we used In-line orifice mixer for efficient chemicals mixing in water treatment. The method of using In-line orifice mixer has been already proved the improvement of water treatment efficiency. Numerical study was performed using FLUENT, a commercial code, to standard design and production of effective In-line orifice mixer. As variable for exactly standardizing, a proper ratio between an outer diameter of cone and a diameter of pipe, a distance between cone and orifice, a determination of orifice diameter for an optimal mixing, a distance between injection nozzle's position and cone, Numerical study has been performed for optimal standard and analyzed flow field on a basis of turbulent intensity in an orifice downstream.

• 환경위생공학
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• 제15권3호
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• pp.70-74
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• 2000

The technology of malodorous substances treatment was classified physical separation and chemical destruction. This study was carried out to investigate the characteristics of malodorous substances treatment with the change of operating conditions from the ozone generator. The major results of this study were as follows : Removal efficiency by additive ozone rate was measured $NH_3$:95%(ozone additive rate : 2), $H_2S$ : 97%(ozone additive rate:4), $CH_3SH$ : 96%(ozone additive rate : 3), $(CH_3)_2S_2$ : 97%(ozone additive rate:5), $(CH_3)_3N$ : 95%(ozone additive rate : 1), $CH_3CHO$ : 95%(ozone additive rate : 2), $C_6H_5CHCH_2$ : 95%(ozone additive rate : 2).

• 열처리공학회지
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• 제8권4호
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• pp.326-332
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• 1995

Using natural frequency measurement method, which is one of NDT method, natural frequency of the hot-rolled mild steel plate(specimen) under fatigue loading was measured. Between the degradation of the specimen under fatigue loading and the variation of the natural frequency of the specimen was investigated. As a result, the degradation of the specimen was described and monitored as variation of natural frequency of specimen. The natural frequency of specimen decreased gradually under fatigue loading. This means the variation of material properties of specimen. Especially. It means the variation of Young's modulus of specimen.

• 대한치과기공학회지
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• 제30권2호
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• pp.71-77
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• 2008

Acrylic resin has been widely used for dental care since it requires relatively simple equipment for treatment and less time and cost are needed to make it and, furthermore, proper strength, dimensional stability as well as durability are ensured after treatment. A survey of denture users showed, however, that more than 60% of dentures installed need repair each year, $22{\sim}30%$ of which are due to falling out of teeth. This study is aimed at exploring the means to increase bonding strength of denture by reducing the causes for falling out of teeth during the processing of dentures. For this aim, the bonding strength of dentures was compares and analyzed before and after the glazed surface of teeth contacting denture was eliminated. From the analysis, it was revealed that there was a difference of 4.3MPa in average in bonding strength between 20MPa for the glazed surface not eliminated and 24.3MPa for the glazed surface eliminated.