• 한국항해항만학회지
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• 제46권6호
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• pp.562-569
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• 2022

기존 운항선박에 적용되어 있는 알람 모니터링 기술은 온도, 압력 등의 데이터 항목을 AMS(Alarm Monitoring System)으로 관리하고 해당 센싱 데이터가 정상 수준 범위를 초과할 경우만 선원에게 알람을 제공한다. 또한 기존 선박의 정비는 PMS(Planned Maintenance System)를 따른다. 이는 장비로부터 측정된 센싱 데이터가 설정범위 이상으로 측정되어 이에 따른 알람을 통해 정비하거나, 대상 기기의 고장 유무에 관계없이 일정 시간 사용 후 해당 부품을 사전에 교체하는 방식으로 운영되고 있다. 하지만 선박 기관운영의 신뢰성과 운항 안전성을 확보하기 위해서는 실시간 상태 모니터링 데이터 기반의 사전적 진단 및 예측이 가능해야 한다. 그러기 위해서 실선 데이터를 종합적으로측정하여 데이터베이스화 하고 이를 선박의 보조기기와 배관의 상태기반 예지보전을 위한 상태 진단 모니터링 시스템을 구현하고자 한다. 특히 반응형 웹 기반으로 선박의 보조기기와 배관 상태 정보를 관리할 수 있도록 하였으며, 선내 개인용 컴퓨터(Personal Computer, PC)에서 보는 용도뿐만 아니라 스마트폰 등 다양한 모바일 기기의 접근 및 활용이 가능하도록 화면과 해상도에 맞춰 최적화된 상태 관리가 가능하도록 하여 업데이트 비용이 적게 들며, 관리 방법도 쉽다. 본 논문에서는 자율운항선박 핵심 기술인 상태기반정비(Condition Based Management, CBM) 기술력을 확보하기 위해 선박의 보조기기 중 펌프와 청정기, 그리고 배관 중 해수 및 스팀 배관의 상태 진단 모니터링을 통해 이상 현상을 파악하고, 이를 통해 융합 분석할 수 있도록 선박 보조기기 및 배관의 성능 진단 및 고장 예측에 활용하여 예방정비 의사결정을 지원하고자 한다.

• Environmental Engineering Research
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• 제21권2호
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• pp.109-120
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• 2016

Conventional treatment techniques cannot meet the stringent modern water quality regulations emanating from the need to provide high quality drinking water. Therefore, a number of studies have suggested low pressure membrane filtration as a worthwhile alternative. However, a major constraint to the extensive use of this technology in low and middle income countries is the high operating and maintenance costs caused by the inherent predisposition to membrane fouling. Notwithstanding, pretreatment of feed water using techniques such as coagulation, adsorption, oxidation and bio-filtration is believed to control fouling. In this review paper, the existing scientific knowledge on membrane fouling and pretreatment techniques for controlling fouling in low pressure membranes is analyzed with the aim of providing new and valuable insights into such techniques, as well as unveiling crucial issues noteworthy for further studies. Among the techniques reviewed, coagulation was observed to be the most cost-effective and will remain the most dominant in the coming years. Although oxidants and magnetic ion exchange resins can also control fouling, the propensity of oxidants to form health treating precursors and the high economic implications of magnetic ion exchange resins will hinder their adoption in developing countries.

• 한국도로학회논문집
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• 제11권3호
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• pp.33-40
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• 2009

폐타이어 고무분말은 도로 유지 및 보수제로 아스팔트 바인더의 개질제로 사용되고 있다. 도로보수제인 폐타이어 고무분말 개질 아스팔트 (crumb rubber modified asphalt, CRMA) 실란트에 필요한 접착특성은 저온에서 아스팔트 바인더의 취성과 접착파괴특성 때문에 주목받고 있다. 본 연구에서는 저온에서 CRMAs의 개질제로서 유연제의 영향을 조사하였다. 저온에서 CRMAs의 특성은 침입도, 연화점, 인장 및 인장접착시험을 통하여 측정하였다. 유연제를 도입한 CRMAs에서 CR과 아스팔트바인더의 연성변형이 증가함에 따라 인장접착강도와 변형률이 증가하였다. 저온영역에서 CRMAs의 인장특성과 접착특성은 유연제의 함량이 중요한 요소임을 발견하였다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권5호
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• pp.357-367
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• 2022

Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 ㎍/kg for 4 min for induction, followed by maintenance of 0.4 ㎍/kg/h. Group F received an infusion of fentanyl 1 ㎍/kg over 4 min for induction, followed by maintenance at 1 ㎍/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation-Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44-6.2) vs. 6.25 (4.21-7) minutes in groups D vs. F (P=0.001), respectively, while the corresponding awakening times were 19 (18.75-21) and 22.5 (22-24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.369-374
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• 2002

This paper presented the development trend of UPS and SPS system has focused on large scale system and more convenient system to maintenance and management. In this paper, we proposed low price and high performance SPSs which can de voltage regulation, harmonic reduction, and capable capacity extension in power. These SPSs are composed by two SPSs in their functional structure, one is power control part including voltage regulation and instant voltage compensaton. The others part is web based monitoring and trend management part for more convenient to SPS operator.

• 기술사
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• 제42권1호
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• pp.44-48
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• 2009

About past 30 years, we don't have enough consideration and investigation about DB-Load. While 30 years, weight of truck is heavier and condition of roads differ, so many conditions of roads and vehicles are changed. We must consider change of many conditions and we must improve laws about maintenance of DB-Load. and now we must consider that low grade as well as high grade bridge can cross heavy vehicle and harmony between changed size of vehicle and bridge while making laws and code. So we can apply to improve design properly.

• ETRI Journal
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• 제34권5호
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• pp.775-778
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• 2012

We propose integrating random network coding with the Enhanced On-Demand Multicast Routing Protocol (E-ODMRP). With the Network Coded E-ODMRP (NCE-ODMRP), we present a framework that enables a seamless integration of random linear network coding with conventional ad hoc multicast protocols for enhanced reliability. Simulation results show that the NCE-ODMRP achieves a nearly perfect packet delivery ratio while keeping the route maintenance overhead low to a degree similar to that of the E-ODMRP.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.242-248
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• 2007

In this paper, the basic requirements of catenary in railroad traction is explained. Three different types of catenary suspension systems for different terrains, environments and high speed / low speed trains are presented. The essential requirements of catenary such as reliability, cost effectiveness, maintenance and ruggedness requirements are discussed. The catenary materials and safety problems associated in it are dealt.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.141-143
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• 2002

Litrex Ink Jet equipment offers prospect for reliable and low cost manufacturing process for PLED technology. The design concept of 140P system that we are developing meets requirement of process/equipment for PLED manufacturing line in terms of higher mechanical accuracy, in-line monitoring system of print head, high precision of process capability, reasonable through-put, high reliability/easier maintenance and no particle generation.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.203-204
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• 2003

Ammonia in aquaculture system may lead to suppression of fish growth, sublethal histopathological changes, and even death thus ammonia is considered toxic to fish. Tricking filter and submerged filter have many advantages include: low construction cost, easy management and maintenance, and well adaptation to different water and waste loading rates. (omitted)