• 한국산업융합학회 논문집
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• 제23권5호
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• pp.835-842
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• 2020

This paper considers a method of reproducing abnormal and fault operation for smart monitoring of thrust bearing used in wave power generation system. In order to develop smart monitoring technology, abnormal and failure data of actual equipment are required. However, it is impossible to artificially break down the actual equipment in operation due to safety and cost. To tackle this problem, a test bed that can secure data through reproduction of a faulty operating environment should be developed. Therefore, in this study, test bed that can reproduce each situation was developed and the operation result was analysis after identifying the situation to be reproduced through the failure factor analysis of the thrust bearing.

• 한국물환경학회지
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• 제25권2호
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• pp.306-310
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• 2009

Packed-bed reactor for removing ammonia was tested at different loading rates. Nitrifiers for ammonia removing was encapsulated in gel media which consisted of polyethlene glycol, alginate and activated carbon. The removal efficiency was nearly 100% when ammonia loading was $12g/m^3/hr$, and the maximum elimination capacity (EC) achieved on this study was $18g/m^3/hr$. The initial microbial portion of nitrifiers in the media was about 82% and it was increased to more than 90% at the end of the operation. Short-term shock loading test was carried out to survey the stability of the media. The inlet loading rates were varied from 2 to $20g/m^3/hr$. The packed-bed reactor overcame the shock loading i.e. removal efficiency recovered rapidly from about 80% to almost 100% within 6 hrs. The results of Live/Dead cell test showed that nitrifiers maintained there activity in the encapsulated media during the test and also against ammonia shock load.

• 한국항행학회논문지
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• 제24권1호
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• pp.9-15
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• 2020

최근 KF-X (Korean Fighter eXperimental)사업에서 AESA (Active electronically scanned array) 레이다, EO-IR (electro-optical and infrared) 및 IRST (infra-red search and track) 센서 등의 개발이 진행되고 있으며 현재 AESA 레이더는 비행 시험을 위한 사전 연구가 진행되고 있다. 본 논문은 AESA 레이다 개발에 따른 선진국의 FTB(Flying Test Bed) 항공기 운영 사례를 중점 분석하고, 이 사례를 중심으로 국내 레이다 개발 시험을 위한 비행시험 항공기의 선정 시 요구사항과 고려사항을 검토하였다. 그에 따른 우리는 FTB 항공기가 국내 환경에서 운영하기 위한 감항 관련 국내 관련 법규를 검토하고 FTB 항공기의 운영하기 위한 방안을 살펴본다. 따라서 우리는 국내 환경에 적합한 FTB 항공기 선정, 감항 및 운영 방안을 제시하고 한다.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.208-219
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• 2023

Recently, as mega-urbanization progresses, urban logistics centered on large cities is growing rapidly, and logistics transportation is increasing due to the lack of logistics infrastructure and the operation of a delivery system using cargo trucks in the city center. being cited as a cause. In order to solve this problem, domestic researchers are conducting research on the development of " Urban Underground railway Logistics System" that minimizes the initial infrastructure construction cost by utilizing the existing urban railway facilities in the city. Therefore, this paper analyzed the usage environment of the actual urban railway station to which the system will be applied in order to derive candidates for the test bed selection of "Urban Underground railway Logistics System". The evaluation criteria for test bed candidate role selection were established, and the candidate group derived from the Brown & Gibson model was used to evaluate the candidate group and derive the candidate role. A review of the results was conducted to contribute to the establishment of a test bed for the " Urban Underground railway Logistics System" under development.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1937-1942
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• 2007

Bimodal tram is being developed to be completed in 2010 and the infrastructure needs to be developed to make the operation in time. Through the study of infrastructure reflecting domestic condition, dedicated lane, station, connection center, automated operation, precise docking, ticketing system, information system, management system for operation and maintenance, and refueling station will be developed and their performances will be also verified through the construction of test bed. The economical, safe and environment-friendly operation of the bimodal tram will be established through the present study.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권3호
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• pp.14-24
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• 2021

Aquifer thermal energy storage (ATES) system uses groundwater thermal energy for cooling and heating of buildings, and it is also often utilized to provide warm water to crops and plants for the purpose of enhancing agricultural yields. This study investigated the potential influences of a ATES system on the geochemical properties of groundwater by simulating the variation of hydrochemistry and saturation index of groundwater during ATES operation. The test bed was installed at an agricultural field, which is mainly composed of an groundwater-rich alluvial plain. The simulation results showed no significant precipitation of mineral phases such as manganese-iron oxide, carbonate and sulfate around the ATES test bed, as well as no debasement of other important water quality parameters. The implementation of ATES system in the study area was appropriate and effective for utilizing the thermal energy of groundwater for agricultural use.

• ETRI Journal
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• 제38권5호
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• pp.911-921
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• 2016

This paper presents the description, practical implementation, and stability analysis of a recently proposed, energy-efficient, medium access control protocol for wireless sensor networks, ALOHA-Q, which employs a reinforcement-learning framework as an intelligent transmission strategy. The channel performance is evaluated through a simulation and experiments conducted using a real-world test-bed. The stability of the system against possible changes in the environment and changing channel conditions is studied with a discussion on the resilience level of the system. A Markov model is derived to represent the system behavior and estimate the time in which the system loses its operation. A novel scheme is also proposed to protect the lifetime of the system when the environment and channel conditions do not sufficiently maintain the system operation.

• 한국지리정보학회지
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• 제16권3호
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• pp.180-192
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• 2013

최근 정보통신의 발달은 유비쿼터스, 스마트 환경이라는 새로운 패러다임을 출현시켰으며, USN 기술은 유비쿼터스 환경 구축 및 적용에 적합한 대표적인 기술이다. 본 논문은 USN 기술을 도시에 적용 검증하기 위한 테스트베드 구축과 적용 사례에 대해 연구하였다. 또한 USN 기술의 공공부분 수요 창출을 위하여 지리정보체계(GIS) 및 시설물관리(FM) 등과 융합하여 도로 위험구간모니터링 서비스 구현 방법에 대해 기술하였다. 실제 적용을 위해, USN 장치 제작 및 현장 설치, 관련 규정 조사, 설치 가이드라인 작성, 시스템 구축 및 실시간 연동 테스트 등을 연구하였다. 본 연구 내용을 도로에 적용하면 도로 공공시설물 관리, 도로 사고 실시간 감시 및 주변 환경 데이터 실시간 모니터링 등 많은 응용이 가능하며 향후 시설물 인프라의 BIM과 접목하면 3차원 시설물관리까지 확장이 가능할 것으로 예상된다.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1059-1067
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• 2006

AODV(Ad-hoc On-Demand Distance Vector) 라우팅 프로토콜은 Ad-hoc 네트워크에서 이동 노드를 사용할 수 있도록 제안된 라우팅 프로토콜이다. AODV 라우팅 프로토콜을 사용하는 Ad-hoc 네트워크에서 고속으로 이동하는 노드가 포함되어 있는 경우 항상 최적 경로를 확보할 수 없는 문제로 인하여 경로 단절과 전송 지연이 발생한다 따라서 본 논문에서는 고속으로 변화하는 네트워크의 토폴로지에서 항상 최적의 경로를 확보 할 수 있는 메커니즘을 통하여 경로의 단절과 전송 지연을 최소화할 수 있는 AODV를 기반으로 하는 라우팅 프로토콜을 제안하였으며 ns2 시뮬레이터를 이용하여 제안 프로토콜을 평가하였다. Ad-hoc 네트워크를 위한 여러 가지 기반 기술의 검증을 위하여 실제의 Ad-hoc 네트워크 테스트 베드를 구현하였다. 본 논문에서는 AODV 라우팅 프로토콜, NAT, Netfilter등의 Ad-hoc을 위한 소프트웨어 검증을 위한 많은 이벤트 메시지를 성능 저하 없이 동작시킬 수 있는 고성능의 임베디드 시스템을 설계 개발하였다. 개발된 하드웨어를 이용한 Ad-hoc 네트워크 테스트 베드에서 AODV 라우팅 프로토콜의 정상 동작과 기존 인터넷 망과의 연동을 확인하였다.

• 한국물환경학회지
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• 제27권6호
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• pp.862-867
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• 2011

Pozzolanic-based stabilization/solidification (S/S) is an effective and economic remediation technology to immobilize heavy metals in contaminated soils. In this study, quick lime (CaO) was used to immobilize cadmium and zinc present in waste mine contaminated clayey sand soils. Addition of 5% quicklime to the contaminated soils effectively reduced heavy metal leachability after 2 bed volume operation below the drinking water regulatory limits. Lime addition was revealed to increase the immobilization for all heavy metals in tested pH ranges, so it could be an optimal choice for short-term remediation of heavy metal contaminated soil. The mass balances for these column tests show metal reduction of 92% for Cd and 87% for Zn of total resolved mass in case of 5% lime application.