• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.393-397
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• 2001

The innovatory process, that is the direct separation and recovery of the iron and zinc metals contained in the high temperature exhaust gas generated from the electric arc furnace fer the inn scrap melting and/or the dust treatment, has been proposed. This proposed process consists of the moving coke bed filter that is directly connected to the electric furnace, and the following heavy metal condenser. The exhaust gas passes through the filter and the condenser right after exhausting from the electric furnace. The moving coke bed filter is being controlled at about 1000℃ and collects iron and slag components contained in the high temperature exhaust gas. Heavy metals such as zinc and lead pass through the filter as vapor. Based on the thermodynamic considerations, the iron oxide and the zinc oxide are reduced in the filter. The solution loss reaction rate is comparatively low at about 1000℃ in the coke bed filter by the analysis using the mathematical simulation model. The heavy metal condenser is installed in the position after the coke bed filter, and rapidly cools the gas from about 1000℃ to 450℃ by a full of the cooling medium like the solid ceramic ball in addition to the cooling from the wall. The zinc and lead vapor condense and separate f개m the gas in a liquid state. The investigation of the characteristics of the exhaust gas of the commercial electric arc furnace, the fundamental experiments of the laboratory scale and the bench scale ensured the formation of this proposed process. A small-scale pilot plant examination is carrying out at present to confirm the formation of the process. It is certain that the dust generation of the electric arc furnace is extremely decreased, and it can save the energy consumption of usual dust treatment processes by the realization of this process.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.421-421
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• 2005

• 한국물환경학회지
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• 제36권4호
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• pp.275-283
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• 2020

Fecal coliforms are indicator bacteria to evaluate fecal contamination and microbiological safety in environment water. To examine fecal coliforms by membrane filtration, 1% rosolic acid solution dissolved in sodium hydroxide(0.2 M) should be added to m-FC medium according to Korean standard method. To reduce the exposure of researchers to harmful chemicals and expenditure of unnecessary cost, we evaluated if the rosolic acid solution is required to detect fecal coliforms. For 113 samples collected from five intake sources of Seoul, 42 samples of six tributaries, and 11 samples of sewage, the number of fecal coliforms was compared in medium with or without the reagent. As a result, the number was higher in m-FC medium without the reagent, but there was not a statistically significant difference. In the water intake, m-FC medium without the reagent could be used to examine fecal coliforms except in July, August and in case of rainfall. When heterotrophic plate counts exceeded 1,000 CFU/filter, or during rainfall, there was an effect of background bacteria in two types of the medium. However, it was more appropriate to use m-FC medium with the reagent to suppress gram-positive bacteria that can grow on medium without the reagent. In the tributary and sewage samples, the effect of the background bacteria was low, allowing the use of medium without the reagent regardless rainfall. Thus, it is necessary to present in standard method that the addition of rosolic acid solution in m-FC medium can be selected according to the characteristics of samples.

• 한국통신학회논문지
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• 제17권2호
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• pp.121-131
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• 1992

포스트 필터링(adaptive postfiltering)을 수신단의 마지막에세 수행 하였다. 첫째는, SBC 시스템의 대역 필터를 QMF(Quadrature Mirror Filter) 대신 GQMF(Generalized QMF)를 사용하여 성능을 향상시켰고, 둘째는, 각 대역에 적응 비트 할당을 함으로써 음질의 향상뿐 아니라 variable rate 부호화할 수도 있었다. 세번째로는 APCM(Adaptive Plulse Code Modulation)과 ADPCM(Adaptive Differential Pulse Code Modulation)을 부호화기로 사용하여 각각의 성능을 평가 한 결과, SB-APCM 의 성능이 우수하였다.또한, 수신단의 마지막에서 적응 포스트 필터링을 수행하여 부호화된 음성의 음질을 개선할 수 있었다. 본 논문에서는 두가지의 적응 포스트 필터링 기법을 제안하였는데 낮은 복잡성을 가지고도 부호화된 음성에서 상당량의 잡음 감쇄를 이룰 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제24권6호
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• pp.1-9
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• 2019

Hard disks, which have long been used as secondary storage in computing systems, are increasingly being replaced by solid state drives (SSDs), due to their relatively fast data input / output speeds and small, light weight. SSDs that use NAND flash memory as a storage medium are significantly different from hard disks in terms of physical operation and internal operation. In particular, there is a feature that data overwrite can not be performed, which causes erase operation before writing. In order to solve this problem, a hot data for frequently updating a data for a specific page is distinguished from a cold data for a relatively non-hot data. Hot data identification helps to improve overall performance by identifying and managing hot data separately. Among the various hot data identification methods known so far, there is a technique of recording consecutive write requests by using a Bloom filter and judging the values by hot data. However, the Bloom filter technique has a problem that a new bit array must be generated every time a set of items is changed. In addition, since it is judged based on a continuous write request, it is possible to make a wrong judgment. In this paper, we propose a method using a counting filter for accurate hot data verification. The proposed method examines consecutive write requests. It also records the number of times consecutive write requests occur. The proposed method enables more accurate hot data verification.

• 유기물자원화
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• 제18권3호
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• pp.87-91
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• 2010

목재 및 비목재 재료는 여과재료로 광범위하게 사용되고 있다. 작은 입자(${\sim}5{\mu}m$)를 여과하는데 사용될 수 있는 구조를 가지기 때문이며, 상대적으로 원가가가 저렴한 재료이다. 이 화이버 필터는 비점오염원을 여과하는데 있어서 목재 및 비목재 재료의 몇 가지 물리적 성질, 특히 입자의 여과에 관하여 주목을 받는 차별화되는 특성을 가지고 있다. 또한, 이들 재료는 각각의 섬유들이 가지는 다양성과 형태로 인하여 비정형성과 복잡한 다공성구조를 형성한다.

• 상하수도학회지
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• 제19권2호
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• pp.149-154
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• 2005

Conventionally used flocculation tanks require large space and high energy requirement for mixing. Static flocculators using gravel bed filter operate at a lower flow rate ($5-10m^3/m^2{\cdot}h$). Further, the cleaning of this system is difficult. A novel high rate static flocculator/filter developed at UTS packed with buoyant media such as polystyrene, polypropylene has been found to operate at higher filtration rates (30-45 $5-10m^3/m^2{\cdot}h$). They can easily be cleaned with minimal energy. Detailed experiments conducted with an artificial kaolin clay solution show that buoyant media is an excellent static flocculator in producing uniform filterable microflocs (12-15 m) even when it is operated at a high rate of 30-40 m/h. Detailed filtration experiments were conducted in a wastewater treatment plant to treat the biologically treated effluent with a floating media of depth of 120 cm. This filter was able to remove majority of phosphorus and remaining solids. It reduced significantly the fecal coliforms and fecal streptoccoci, thus requiring less amount of chlorine for disinfection. The advantage of this system is the low energy and water requirement for cleaning of filter bed. The periodic backwash adopted 30 seconds air and water and 30 seconds water cleaning every 90 minutes filter operation. Thisis equivalent to 1-2% of filtered water production. Mechanical cleaning system on the other hand, requires very low energy requirement (<1% of filtered water production).

• Journal of Plant Biotechnology
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• 제31권3호
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• pp.209-217
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• 2004

기내 배양환경을 조절하여 건전한 유식물체를 획득하기 위해 도라지를 무균발아시켜 shoot부분을 NAA 0.1 mg/L가 첨가된 MS 기본배지에 치상한 후 membrane filter 부착 유무와 sucrose 농도를 달리 처리하여 생장반응을 조사하였다. Membrane filter 미부착구에서는 배양용기 내의 $CO_2$와 $C_2$H$_4$ 농도가 membrane filter 부착구에 비해 높았으며 membrane filter가 부착되지 않았을 때 $CO_2$ 농도는 배양기간이 경과될수록 증가하였으나 $C_2$H$_4$ 농도는 감소하는 경향이었다. 식물체 생장은 membrane filter 부착구가 미부착구에 비해 양호하였고, 미부착구에서는 sucrose 농도가 증가할수록 생육이 양호하게 나타났다. 생체중과 건물중은 membrane filter를 부착하지 않은 sucrose 4.5% 처리구에 비해 membrane filter를 부착한 sucrose 무첨가구에서 비슷하거나 높았다. 엽록소 함량은 membrane filter 부착구에서 미부착구에 비해 높았으며 당 함량도 비슷한 경향이었는데 두 처리간 차이는 더 컸다. 기공은 membrane filter 부착구에서 미부착구에 비해 닫혀 있었으며 엽육조직은 membrane filter를 부착하거나 sucrose 농도가 높을수록 잘 발달하였다. 또한 상토에 이식한 후 13일째 생존율은 sucrose 처리 농도에 관계없이 membrane filter 미부착구는 0%인데 비해 부착구는 100%로 나타났다.

• 한국작물학회지
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• 제42권5호
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• pp.615-625
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• 1997

Indica 벼의 원형질체들로 부터 효과적인 식물체 재분화 방법을 개발하였다. 이 방법은 배형성 진탕 세포 배양체로 부터 나출된 원형질체들을 feeder cell들이 agarose에 embedded된 배지 표면에 놓인 filter membrane 위에 배양하는 것이다. Feeder cell로서 Lolium multiflorum 세포배양체를 사용했을 때가 Oryza ridleyi를 사용했을 때보다 효과적이었고, 원형질체 평탄효율은 세포 배양체 age에 따라 달랐지만 최고로 0.68％ 까지 증가되었다. Carbohydrate source로서 maltose를 사용하거나 maltose와 sucrose를 1:1로 조합했을 때가 sucrose 단독으로 사용했을 때보다 식물체 재분화율이 증가되었고, 고농도의 agarose를 이용하여 원형질체로부터 유도된 캘러스를 dehydration시켰을 때 또한 재분화율이 괄목하게 증가되었다. 식물체 재분화율은 control 캘러스로부터 3.1∼30.6％ 였지만 dehydration처리한 캘러스로부터는 30.7∼70.7％까지 증가되었다. 원형질체로 부터 유도된 식물체들은 형태적으로 정상이며 개화했다.

• 자원리싸이클링
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• 제9권4호
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• pp.44-49
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• 2000

중저타소페로망간을 제조하는 AOD공정의 bag filter에 포집된 분진은 약 63%의 Mn을 함유하며, XRD로 분석된 결정체는 Mn$_{3}O_{4}$이지만, 질산으로 Mn을 침출하면 MnO$_{2}$가 잔류되기 때문에 67%이하의 침출율을 나타낸다. 따라서 활성탄으로 환원배소한 후에 침출하는 방법과 침출시에 활성탄을 첨가하는 방법으로 침출율을 높이고자 하였따. 70$^{\circ}C$, 0.5N HNO$_{3}$ pilp density 7 g/l 의 액에 분진된 10%이상으로 활성탄을 첨가하면 90%이상의 Mn이 침출되었고, 5%의 활성탄을 혼합하여 750$^{\circ}C$에서 배소한 분진은 상온에서 6N HNO$_{3}$에 150 g/l을 첨가하였을 때에 99%이상의 Mn이 침출되었다.