• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.595-601
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• 1997

The regeneration of the iron powders in the treatment of $FeCl_3$ etching solution containing nickel by ball-mill and ultrasonic treatments has been studied. When the unreacted iron powders were treated twice, the removal efficiency of nickel was 94.0% for the ball-mill treatment and 82.1% for the ultrasonic treatment. But the removal efficiency of nickel was 40.0% for the untreated iron powders. As the treatment time was increased, the particle size of iron powders was decreased for ball-mill treatment and almost not changed for ultrasonic treatment.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.695-704
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• 2003

This paper proposes a new scheduling technique to play multimedia data streams in mobile terminals. The paper explores the characteristics of multimedia data streams , firstly. On basis of these characteristics, selection of specific data stream can be possible as well as transcoding protest. Our approach aims at reducing the early-stage delay time more effectively since it makes possible to select and transcodes some specific streams by employing a selection policy rather than transcoding all streams in the playing process Thus, this paper suggests a stream selection policy for the transcoding based on EPOB (End Point of Over Bandwidth). It aims to lower the required bandwidth of multimedia streams than the network bandwidth level and also to minimize early-stage delay time for multimedia streams, which is to be played in mobile terminals.

• 한국데이터정보과학회:학술대회논문집
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• 2001.10a
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• pp.34-41
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• 2001

본 논문에서는 비재생보증을 갖는 수리 가능한 시스템에 대한 베이즈 관점에서의 최적의 교체정책을 제안한다. 비재생무료보증(non-renewing free-replacement warranty : NFRW)과 비재생비례보증(non-renewing pro-rata warranty : NPRW)의 두 가지 경우에 대하여 각각 기스템의 고장시간이 와이블분포일 때 베이즈 관점에서의 단위시간당 기대비용을 최소화하는 최적의 교체정책과 순응적 교체정책에 대하여 설명한다.

• Applied Chemistry for Engineering
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• v.2 no.1
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• pp.38-46
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• 1991

Regeneration of Ni catalyst deactivated by carbon-deposition and sulfur-poisoning was studied. When a carbon-deposited catalyst was regenerated by hydrogen, the final recovery of catalytic activity for benzene hydrogenation was large but relatively long period of regeneration was required, and futhermore the deposited carbon could not be removed completely. In case of oxygen-treatment, the regeneration rate was high and the deposited carbon could be removed almost completely after a subsequent reduction treatment. When a sulfur-poisoned catalyst was regenerated by hydrogen and water vapor, the catalytic activity was not recovered. The regeneration treatment with oxygen at $650^{\circ}C$ recovered the catalytic activity up to 60 % of the initial value. When $Cl^-$ was added to oxygen, the activity was easily recovered to 45 % of the initial value even after treatment at $500^{\circ}C$. Sintering of the dispersed Ni particles was enhanced by water vapor but was hindered by oxygen and chlorine addition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.493-505
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• 2003

A new inter-client synchronization framework for multicast media streaming is proposed employing a server-client coordinated adaptive playout control. The proposed adaptive player controls the playback speed of audio and video by adopting the time-scale modification of audio. Based on the overall synchronization status as well as the buffer occupancy level, the playout speed of each client is manipulated within a perceptually tolerable range. Additionally, the server implicitly helps increasing the time available for retransmission while the clients perform an interactive error recovery mechanism with the assistance of playout control. The network-simulator based simulations show that the proposed framework can reduce the playout discontinuity without degrading the media quality, and thus mitigate the client heterogeneity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.449-458
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• 2023

As an adsorption technology for dissolved organic matter, the adsorption capacity of granular activated carbon, GAC, can be applied, but activated carbon whose adsorption capacity is significantly reduced by use is inevitably replaced or regenerated. However, due to the economics of replacement cost, thermal regeneration method is used commercially, but high energy cost and loss of activated carbon occur under high temperature conditions above 800℃. In this study, the Sono-Fenton method, a multi-oxidation technology that combines Fenton oxidation and ultrasonic oxidation, was applied to improve the regeneration efficiency of spent GAC used to treat dissolved organic matter in combined sewer overflows (CSOs), and the regeneration efficiency of spent GAC by oxidant and ultrasonic frequency was investigated. In the applied Sono-Fenton treatment, the highest regeneration efficiency of 68.5% was obtained under the regeneration conditions of Fe²⁺ 10 mmol/L, H₂O₂ concentration 1,000 mmol/L, ultrasonic treatment time of 120 min, and ultrasonic frequency of 40 kHz. And similar efficiency was also obtained at 750 kHz, while ultrasonic waves of other frequencies had poor regeneration efficiency, and the magnitude of frequency and GAC regeneration efficiency did not show a linear relationship. In the case of continuous operation of the GAC adsorption tower with CSOs prepared by diluting raw sewage, about 700 hours of operation without regeneration was possible, and as a result of applying one Sono-Fenton treatment, 40-70% COD_cr removal efficiency was obtained during a total of 1,000 hours of GAC adsorption operation.

• Applied Microscopy
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• v.35 no.1
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• pp.15-22
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• 2005

Metallothionein (MT) is a low molecular weight, cysteine-rich, metal-binding, and non-enzymatic protein. The present study was carried out to investigate the expression of MT gene as well as the localization of MT in regenerating rat liver. In partial hepatectomized rats, MT mRNA was detected as early as 1 hr and reached a maximal level by 8 hr after the operation. Thereafter, this level decreased gradually until 24 hr, and it became similar to that of sham control. Meanwhile, time course of MT immunoreactivity using immunogold-labelling revealed that the number of gold particles in hepatocytes increased significantly by 12 hr, but decreased at 48 hr after partial hepatectomy. Ultrastructurally, immunogold particles indicating the presence of MT were distributed in both the cytoplasm and the nucleus of the rat hepatocytes, particularly the particles were distributed at rough endoplasmic reticulum and nucleolus and did not seem to adhere to mitochondria or lysosomes in proliferating hepatocytes. Briefly, high level of MT mRNA expression and the intense immunoreactivity and/or the specific localization of MT was observed during liver regeneration. These results suggest that MT possibly involves hepatocyte proliferation via the storage or the supply of various metal ions in the regenerating rat liver.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.35-36
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• 2019

최근 해양 전투체계에서는 사후분석에 대한 기능이 중요시 되고 있다. 그 이유는 사후분석을 통해 작전을 분석하고 더 나은 작전을 수행할 수 있기 때문이다. 이를 가능하게하기 위해 해양 전투체계에는 전술정보 기록 및 재생 기능이 탑재되어 있다. 전술정보 기록 및 재생은 작전상황에서 전투체계 콘솔에 전시된 전술정보들을 기록해서 사후분석 및 평가를 위해 재생하는 기능이다. 본 논문에서는 전술정보 기록 및 재생 개발에 대한 효율화 방법을 제시한다. 모델 중심의 개발방식 적용과 재생시간의 효율화를 통해 기존방식 보다 효율적인 전술정보 기록 및 재생 소프트웨어를 개발하는데 그 목적을 가진다.

• The Magazine for Energy Service Companies
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• s.73
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• pp.52-55
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• 2011

'2011 대한민국 녹색에너지대전'이 지식경제부 주최, 에너지관리공단 주관으로 지난 10월 19일 서울 삼성동 코엑스(A,B홀)에서 개최되었다. 올 해로 31회를 맞이한 대한민국 녹색에너지대전은 '세이브 에너지, 스마트 라이프(Save Energy, Smart Life)라는 주제로 13개국, 247개 업체가 참가하였으며, 에너지절약 및 효율 향상 분야, 신재생에너지분야, 기후변화대응분야 등 녹색에너지 분야 전반을 총망라한 최신 녹색기술 제품들이 전시되었다. 이번 전시회는 코트라 주관의 수출상담회, 신재생에너지 유공자 포상이 열렸으며, 일반인 대상의 '신재생에너지 체험관'을 전시기간 내내 운영해 일반 관람객들이 태양광 선풍기 풍력자동차 등을 직접 조립해 보도록 해 관람객들의 호응을 얻었다. 21일 개최된 ESCO투자 사례 발표회에서는 산업체 건물에서 추진된 ESCO 투자 사례 정보를 제공해 주는 뜻 깊은 시간이 되었다. 특히 이번 전시회에는 대내외적으로 에너지절약에 대한 뜨거운 관심이 고조되는 가운데 롯데, LG전자, 삼성전자를 비롯해 효성, 삼천리 등 대기업이 대거 참가, 에너지효율 및 온실가스 저감 최신 기술을 선보였다. 이번 전시회에서는 에너지효율과 신재생에너지에 관심이 많은 관람객들과 최신에너지 기술을 도입하고자 하는 산업체 임직원, 신재생에너지 및 기후 변화대응분야 신규 사업에 관심이 있는 투자자 등 전시장을 찾는 모두에게 유익한 정보를 제공하는 뜻깊은 시간이 되었다.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.1-8
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• 1993

ABSTRACT: Factors responsible for protoplast formation and regeneration of Phytophthora capsici were examined. Protoplasts were successfully liberated from the mycelial culture by digestion for 6-9 hrs with Novozym 234 in 0.35 M $CaCl_2$, (pH 5.7) as osmotic stabilizer. Young rapidly-growing mycelium (24 hrs old) showed highest protoplast yields. High concentrations of Novozym 234 were effective in releasing protoplasts from the mycelium. The combination of 0.4 M mannitol and 0.1 M $CaCl_2$ was optimal osmotic stabilizers for protoplast regeneration. The synthetic Henninger media containing all nutritional elements gave the best regeneration rate. The protoplast regeneration was greatly inhibited in the media which were not supplement with amino acids or ${\beta}-sitosterol$. Certain amino acids such as L-aspartic acid and L-glutamic acid remarkably enhanced protoplast regeneration. However, the addition of microelements did not affect protoplast regeneration.