• 한국환경과학회지
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• 제20권9호
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• pp.1151-1163
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• 2011

The bed change analysis near the opening gate of a dam or weir to release deposited sediments have been conducted mostly using the numerical models. However, the use of unverified input parameters in the numerical model is able to produce the different results with natural and real conditions. Also, the bed changes near the opening gate of a dam or weir calculated with a numerical model could be varied depending on the geometry extent included the downstream area with supercritical flow in the model. In addition, the different time steps could provide different results in the bed change calculation, even though other conditions such as input parameters, geometries, and total simulation time were same. Therefore, in this study, hydraulic experiments were performed to validate the eddy viscosity coefficient which is the one of important input parameters in the RMA2 model and relevant to variation of simulation results. The bed changes were calculated using the SED2D model based on flow results calculated in the RMA2 model with the verified and selected eddy viscosity coefficient and also compared with experimental results. The bed changes near the opening gate were underestimated in the numerical model comparing with experimental results except only the numerical case without the modeling section of sediment release pipe and downstream area where the supercritical flow was produced. For the simulation of minimum time steps, different shapes of scour hole were produced in numerical and physical modeling.

• 수산해양기술연구
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• 제44권3호
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• pp.218-228
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• 2008

This paper describes on the real-time tracking of ship's dynamic behavior by AIS information in the coastal waters. The AIS data was received at a land station by using the antenna of AIS receiver mounted on the rooftop of the laboratory, Pukyong National University (PKNU), Busan, Korea, and stored as a NMEA format of serial output sentence of VDM(VHF Data-Link Message) and displayed on the ENC(Electronic Navigational Chart) of a PC-based ECDIS. In this study, the AIS receiver was mainly used to obtain the dynamic information that is necessary to evaluate and track the movement situation of training ship "KAYA" of PKNU in the coastal waters. The change of position with time for the ship turning under the rudder angle of port $30^{\circ}$ was correctly tracked with the turning circle of 940 m in diameter on the ENC of a PC-based ECDIS. Then, the dynamic information of the AIS system was updated every 6.29 seconds under the turning situation for the speed of 10.9 knots and every 21.65 seconds under the situation running at the speed of 11.05 knots on the straight line route of $155^{\circ}$, respectively. In case of AIS target tracking in the inshore zone behind large topographical obstructions, such as mountain and apartment buildings, the update rate of dynamic information was irregularly changed by the existence of land obstacles. However, the position tracking by AIS information under the situation existing no sea obstructions was achieved in real or near real-time and the instant presentation of course alternations for the ship was correctly monitored by using a PC-based ECDIS. From these results, we concluded that the PC-based ECDIS technology and methodology combined with the AIS information can be easily extended and applied to the surveillance and management for the fishing operation of fishing vessels in the coastal zone and in the EEZ fishing grounds.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권3호
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• pp.132-138
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• 2010

In the present study, the real-time monitoring system is developed based on the wireless sensor network (WSN) and power line communication (PLC) employed in the 3,000-ton-class training ship. The WSN consists of sensor nodes, router, gateway and middleware. The PLC is composed of power lines, modems, Ethernet gateway and phase-coupler. The basic tests show that the ship has rather good environments for the wired and wireless communications. The developed real-time monitoring system is applied to recognize the thermal environments of main-engine room and one cabin in the ship. The main-engine room has lots of heat sources and needs careful monitoring to satisfy safe operation condition or detect any human errors beforehand. The monitoring is performed in two regions near the turbocharger and cascade tank, considered as heat sources. The cabin on the second deck is selected to monitor the thermal environments because it is close to the heat source of main engine. The monitoring results of the cabin show the thermal environment is varied by the human activity. The real-time monitoring for the thermal environment would be useful for the planning of the ventilation strategy based on the traces of the human activity against inconvenient thermal environments as well as the recognizing the temperature itself in each cabin.

• 정보와 통신
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• 제9권9호
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• pp.72-85
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• 1992

다수의 처리 장치가 실시간 실현에 필수적이라는 것이 많은 디지털 신호처리를 일정한 시간 내에 하기 위한 요구 조건이다. VLSI 기술이 발전함으로 많은 기능 장치로 구성된 컴퓨터 시스템을 설계하고, 실현하는 것이 가능하게 되었다. 일정한 시간내에 높은 처리 능력을 갖음으로서 디지털 신호처리에 응용할 수 있는 VLSI 구조를 연구하는데 데이터 통신의 요구량과 계산의 복잡성을 최소화 할 수 있는 알고리듬의 개발이 요구된다. 이 문제를 해결하는 방법으로 DLSI 시스템이나 적응 시스템을 모델로 하는 효과적인 알고리듬을 조사하고 , 이 알고리듬을 실현할 수 있는 VLSI구조와 연관된 멀티 프로세서 시스템을 개발하는데 본 연구의 목적이 있다. 본 연구에서는 실시간 2차원 신호처리를 할 수 있는 새로운 VLSI 구조를 제안했다. 이 VLSI 구조는 칩 내부에서 단일 처리 장치가 갖는 개념을 다수의 처리 장치를 사용하는 경우로 확장하였다. 이 VLSI 구조는 입력 데이타의 크기가 증가함에 따라서 복잡성과 입력당 계산의 수가 증가하지 않는다는 장점을 갖기 때문에 매우 큰 2차원 데이타를 실시간에 처리할 수 있다.

• 한국측량학회지
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• 제28권5호
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• pp.531-537
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• 2010

실시간 공중자료획득 시스템은 긴급상황에서 실시간으로 공간정보를 생성하기 위해 빠른 매핑을 수행하는 시스템이다. 이 시스템은 GPS/INS 통합 알고리즘에서 제공한 위치 및 자세를 사용하여 무기준점 방식의 AT(aerial truangulation)을 수행한다. 따라서 순차적으로 AT을 통한 조정된 위치 및 자세를 얻을 수 있다면, 이를 칼만필터의 측정치로 하여 위치 및 자세를 보정할 수 있다. 이에 본 연구는 무인항공기 기반의 항공시스템을 기준으로 GPS/IMS Image 시뮬레이션 데이터를 생성하였다. 생성된 시뮬레이션 데이터를 이용하여 GPS/INS 통합 알고리즘을 통한 AT 수행결과와 AT을 통해 조정된 위치 및 자세를 이용하여 GPS/INS 위치 및 자세를 보정하는 GPS/INS/AT 통합 알고리즘에 의해 계산된 AT의 결과를 산출하여 비교하였다. 비교분석 결과, GPS/INS/AT 통합 알고리즘으로 AT를 수행한 결과가 GPS/INS를 이용한 AT를 수행한 결과보다 정확성이 높은 것을 확인하였다. 그러나 항체가 회전을 할 경우에는 위치 오차가 GPS/INS로 부터의 위치오차보다 높게 나오는 경향을 보였으며, 추후 분석이 필요할 것이라고 사료된다.

• 한국건설관리학회논문집
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• 제15권2호
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• pp.122-131
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• 2014

플랜트 시장이 성장함에 따라 발주자의 공기단축을 위한 품질, 기술에 대한 요구가 커져가고 있다. 다른 건설 프로젝트에 비하여 플랜트 프로젝트는 방대한 규모와 복잡한 공정으로 인하여 프로젝트 참여자간의 의사소통, 작업의 중복, 오류, 누락, 재시공 등의 문제가 발생하고 있다. 이를 방지하기 위해서는 참여자간 현장에서 부재, 장비, 공사에 관한 정보공유가 실시간으로 이루어져야 한다. 본 연구에서는 효율적인 배관공사관리를 위한 모바일 기반의 NFC, AR기술을 활용하여 프로세스 개선 및 시스템 구축하였다. 본 연구에서 개발된 프로세스 및 시스템은 현장에서 실시간적인 정보공유 및 전달이 이루어질 수 있는 환경 구축을 통하여 현장에서 보다 효율적인 공사관리가 이루어질 것으로 기대된다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1071-1071
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• 2001

Near-infrared spectroscopy (NIRS) is potentially a powerful and revolutionary technology for environmental analysis. It is supported by a large body of scientific and experiential knowledge. The instrumentation is well-developed, with easy-to-use, highly dependable instruments, but at the same time it is still developing, particularly with the production of more portable and rapid instruments, and more powerful software. NIRS is used globally in numerous industries for commodity analysis. Yet NIRS is largely unknown in the field of environmental chemistry and monitoring, and is not even routinely used in soil analysis, where the research literature on NIRS extends over four decades. Part of the explanation for the poor visibility of NIRS is the fact that NIRS is not routinely taught in Chemistry programs in universities, where most environmental chemists and environmental technicians are trained. This presentation examines the unique capabilities of NIRS, such as rapid, real-time analysis; analysis of whole samples; simultaneous analysis of multiple constituents; cost-effectiveness, and portability, as they match needs for analysis in several environmental areas. Examples of NIRS usage and published and unpublished results will be described for such areas as soil and sediment analysis; water quality monitoring; and nutrient loading in application of manures and sewage sludge (biosolids) to land. Present barriers to the use of NIRS in environmental analysis will be discussed. It is argued that emerging environmental problems and increasing attention to some traditional problems will enhance the application of NIRS in the future.

• 천문학회지
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• 제49권4호
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• pp.157-162
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• 2016

High resolution reconstruction technology is developed to help enhance the spatial resolution of observational images for ground-based solar telescopes, such as speckle masking. Near real-time reconstruction performance is achieved on a high performance cluster using the Message Passing Interface (MPI). However, much time is spent in reconstructing solar subimages in such a speckle reconstruction. We design and implement a novel parallel method for speckle masking reconstruction of solar subimage on a shared memory machine using the OpenMP. Real tests are performed to verify the correctness of our codes. We present the details of several parallel reconstruction steps. The parallel implementation between various modules shows a great speed increase as compared to single thread serial implementation, and a speedup of about 2.5 is achieved in one subimage reconstruction. The timing result for reconstructing one subimage with 256×256 pixels shows a clear advantage with greater number of threads. This novel parallel method can be valuable in real-time reconstruction of solar images, especially after porting to a high performance cluster.

• 설비공학논문집
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• 제12권6호
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• pp.609-615
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• 2000

The energy conservation is one of the most important issues in recent years. Especially, the energy conservation through improved control strategies is one of the most highly possible area to be implemented in the near future. The energy conservation of the ice storage system can be accomplished through the improved control strategies. A real time building load prediction algorithm was developed. The expected highest and the lowest outdoor temperature of the next day were used to estimate the next day outdoor temperature profile. The measured dry bulb temperature and the measured building load were used to estimate system parameters by using the on-line weighted recursive least square method. The estimated hourly outdoor temperatures and the estimated hourly system parameters were used to predict the next day hourly building loads. In order to see the effectiveness of the building load prediction algorithm, two different types of building models were selected and analysed. The simulation results show less than 1% in error for the prediction of the next day building loads. Therefore, this algorithm may successfully be used for the development of improved control algorithms of the ice storage system.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1037-1043
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• 2006

본 논문은 인터넷 상에서 동기화된 실시간 미디어 멀티캐스트 서비스에 적합한 오버레이 멀티캐스트 트리를 구성하는 알고리즘을 제안한다. 제안하는 알고리즘은 멀티캐스트 송신 단에서 각 종단 시스템 사이의 전송 지연에 대한 평균과 변이를 최소화하는 트리 구성을 찾는다. 그러나 위의 문제는 NP-완전하므로, 이러한 문제의 계산 복잡도를 낮추면서, 근사해를 찾기 위한 방법으로 OGA (Orthogonal Genetic Algorithm)을 이용하였다. 실험 결과에서 제안하는 알고리즘이 기존 알고리즘에 비해 통기화된 실시간 미디어 데이터 전송을 위한 효과적인 트리를 구성한다는 것을 보인다.