• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.448-454
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• 2000

This study was to examine the physicochemical characteristics of coagulation reaction between ignited oyster shell powder (IOSP) and red tide organisms (RTO), and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea,IOSP was made from oyster shell and its physicochemical characteristics were examined for particle size distribution, surface characteristic by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various c(Incentrations of IOSP, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number, IOSP showed positive zeta potentials of $11.1{\~}50.1\;mV\;at\;pH\;6.2{\~}12.7$, A positive zeta potential of IOSP slowly decreased with decreasing pNa 4,0 to 2,0. When pNa reached zero, the zeta potential approached zero, When a pMg value was decreased, the positive zeta potential of IOSP increased until pMg 3.0 and decreased below pMg 3.0. IOSP showed 4.8 mV of positive zeta potential while RTO showed -9.2 mV of negative zeta potential in sea water. A positive-negative EDL (electrical double-layer) interaction occurred between $Mg(OH)_2$ adsorption layer of IOSP and RTO in sea water so that EDL attractive force always worked between them. Hence, their coagulation reaction occurred at primary minimum on which an extreme attractive force acted because of charge neutralization by $Mg(OH)_2$ adsorption layer of IOSP. As a result, the coagulation reaction was rapidly processed and was irreversible according to DLVO (Deriaguin-Landau-Verwey-Overbeek) theory. Removal rates of RTO were exponentially increased with increasing both IOSP concentration and G-value. The removal rates were steeply increased until 50 mg/l of IOSP and reached $100{\%}\;at\;400\;mg/l$ of IOSP. Removal rates of RTO were $70.5,\;70.5,\;81.7,\;85.3{\%}$ for G-values of $1,\;6,\;29,\;139\;sec^(-1)$at IOSP 100 mg/l, respectively. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction.

• Broadcasting and Media Magazine
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• v.12 no.4
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• pp.53-63
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• 2007

인터넷과 멀티미디어 기술의 발달은 우리에게 다양한 콘텐츠를 손쉽게 접할 수 있는 환경을 제공하였다. 그러나 멀티미디어 콘텐츠의 무분별한 복제와 불법유통으로 인한 저작권 침해는 심각한 사회적 문제로 대두되고 있다. 이에 정부는 저작권법을 전면 개정하면서 강력한 대응책을 마련하고 있다. 특히 개정 저작권법은 동영상, 음악, 게임 등 다양한 콘텐츠에 대한 불법 유통을 방지하고자 특수한 유형의 온라인서비스제공자들의 기술적 조치(필터링)를 의무화하고 있다. 이에 따라 필터링기술에 대한 관심이 높아지면서 해당 온라인서비스사업자(OSP)들은 필터링 기술의 적용을 준비하고 있으며, 기술개발업체들은 법적 기준을 충족시킬 수 있는 필터링 기술의 개발을 위해 노력하고 있다. 본 고에서는 이러한 상황의 배경과 필터링 기술의 개요와 국내외 동향 및 향후 전망을 제시한다.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.207-210
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• 2007

최근 전자파에 일반인에 대한 관심이 높아지고 있고, 기업들의 환경경영의 일환으로 전자파환경 관리도 하나의 이슈로 대두되고 있다. 초고속인터넷서비스 속도개선을 위해 통신장치를 기존의 전화국사내에서 가입자 주택 가까이 또는 주택 건물의 내부로 이동하여 설치하고 있다. 이런 경우 주변 거주자들은 전자파의 인체 유해성에 대한 우려를 하게 되며, 이로 인해 일부 장치설치 곤란하여 서비스제공에 어려움이 발생하기도 한다. 본 논문은 초고속서비스 제공을 위해 가입자 가까이에 설치된 여러 지역의 옥외 통신설비 주변에서 전자파 측정기술을 서술하고 측정된 결과를 국내 기준과 비교 분석하였다. 측정결과 국내 기준보다 매우 낮은 결과를 보였다.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.293-295
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• 2007

OSP 에서 주로 사용되는 Drop Cable 은 통신단말인 단자함에서 통신전주 두상에 설치된 인입클램프 걸이에 인입클램프를 취부하고, 가공구간을 통해 가입자 댁으로 가설을 하며, 가입자 댁의 일정한 지점에 인입벽철 또는 인입용 훅을 설치하고, 인입클램프를 체결하여 Drop Cable 의 이도 및 루트를 고려하여 개통공사를 완성하여 해당서비스를 공급하게 된다. 이때, 사용되는 Drop Cable 은 일반적으로 자기지지를 할 수 있는 "8" 형태의 자기지지형 Drop Cable 을 주로 이용하였으나, 광섬유를 이용하는 FTTH 사업에서는 서비스 개통시 "0" 형태의 Optical Drop Cable(광옥외선)을 사용하여 개통작업의 시공성 및 생산성을 향상 시켰다. 이에 사용되는 적합한 인입광 클램프는 광옥외선의 외형적인 구조에 손상을 전가하여서는 안되며, 광옥외선 내부의 광섬유에 손상을 가하지 않는 최소의 손실을 가지며, 일정한 인장력을 유지하고 있어야 한다. 따라서, 위의 사항을 고려한 인입 광클램프의 특성에 대해 고찰하고자 한다.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.49-64
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• 1997

The purpose of this study is to classify the patterns of consumption deprivation and to compare the level of consumption deprivation by them. For empirical analysis, this study used the data on 563 households in the city of Inchon collected by the researchers through interviews. The statistical methods used in this study were cluster analysis, oneway ANOVA, and crosstabs. four clusters were classified: 'Overall satisfied Pattern (OSP)', 'Food satisfid with Others deprived Pattern (FS-ODP)', Food Extremely deprived with Food Deprive Pattern (HED-FDP)'. Those I FED-HSP tended to be old aged, and those in GED-FDP tended to be urban unstable workers. The results imply that welfare policy for urban poor households should be differentiated by the characteristics of consumption of each pattern of consumption deprivation.

• Journal of Welding and Joining
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• v.31 no.3
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• pp.22-30
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• 2013

Due to ELV banning, automotive electronics cannot use four kinds of heavy metal element (Pb, Hg, Cd, $Cr^{6+}$) from 2016. Therefore, this study was focused on degradation characteristics of Sn-3.0Ag-0.5Cu Lead-free solder joint with OSP and ENIG finsh under various reliability assessment method, as like to thermal shock test and high temeprature/high humidity test with test duration for cabin electronics. Also, we compared bonding strength degradation to other advanced research results of electronic control unit for engine room because of difference service temperature with mount location in automotive. Whisker growth phenomenon and mitigation method which were essentially consideration items for Pb-free car electronics were examined. Conformal coating is a strong candidate for mitigating whisker growth in automotive electronics. Necessary condition to adapt Pb-free in car electronics was shown.

• Review of KIISC
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• v.22 no.3
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• pp.19-24
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• 2012

IT 기술의 발달은 생활의 편리함을 제공하지만 그와 더불어 새로운 사회 문제들을 야기시키고 있다. 그 중에서도 유해 매체의 범람은 자라나는 청소년들에게 가장 심각한 영향을 끼치는 사회 문제이다. 본 논문에서는 클린 인터넷 환경을 제공하여 유해 멀티미디어로부터 청소년을 보호하고 정보복지를 실현시킬 수 있는 현재의 기술적 방법들에 대해 살펴본다. 그리고 최근 유해음란물의 주요 유포경로가 되고 있는 웹 하드 등의 온라인 서비스 제공자(OSP: Online Service Provider) 측면에서 유해음란물이 배포되기 이전에 효과적으로 필터링할 수 있는 방안을 제시한다. 또한, 미디어, 통신, 디바이스, 서비스 환경의 변화에 효과적으로 대처하기 위해 요구되는 유해 멀티미디어 차단 기술의 향후 연구 방향에 대해서도 제안한다.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.101-107
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• 2007

In this paper, we have presented the results of Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) based fiber-to-the-home (FTTH) field trial test which was held in the city of Gwangju. We have implemented an injection locked Fabry-Perot Laser Diode (FP-LD) based WDM-PON system and reliably delivered Internet Protocol TV (IP-TV), networked Personal Video Recorder (N-PVR), High-Definition Video on Demand (HD-VoD), Education on Demand (EoD) and Internet service as FTTH service through the system during the field trial test. We have also verified that the WDM-PON system worked well to provide quality of service (QoS) guaranteed 100Mbps bandwidth per subscriber. Furthermore, we have presented network designing issues in Outside Plant (OSP) and Customer Premises Network (CPN) that should be overcome to efficiently deploy FTTH service. Finally, based on the field trial test results, we proposed FTTH service deployment strategies.

• Electronics and Telecommunications Trends
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• v.35 no.7
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• pp.36-45
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• 2020

The method and process of research and development (R&D) is changing when we develop artificial intelligence (AI), and the way R&D results are dispersed is also changing. For the R&D process, using and participating in open-source ecosystems has become more important, so we need to be prepared for open source. For product and service development, a combination of AI algorithm, data, and computing power is needed. In this paper, we introduce ETRI AI Strategy #4, "Expanding AI Open Platform." It consists of two key tasks: one to build an AI open source platform (OSP) to create a cooperative AI R&D ecosystem, and another to systematize the "x+AI" open platform (XOP) to disperse AI technologies into the ecosystem.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.33-34
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• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.