• 디지털콘텐츠학회 논문지
• /
• 제3권1호
• /
• pp.47-57
• /
• 2002

최근, 정보 통신 기술의 발전에 따라 무선 통신망에서 음성, 데이터, 정지화면, 동영상 및 다양한 멀티미디어 데이터를 추구하고 있다. 효율적인 실시간 멀티미디어 데이터 전송을 위해서는 실시간 데이터의 지연 한계를 보장하고 비실시간 멀티미디어 데이터의 데이터 손실을 최소화해야 한다. 무선 ATM은 유선 ATM을 기본으로 하고 있지만 무선 환경에서의 다양한 서비스에 대한 힘든 전송률과 품질에 따른 문제점들이 수반된다. 그 결과, 무선 통신 환경에서 각각의 트래픽 종류에 따른 품질 서비스(QoS)를 보장하는 방법을 찾는 것이 중요하다. 이 논문에서는 무선 ATM망에서 실시간 멀티미디어 데이터 서비스 전송을 위한 스케줄링 방법으로 개선된 TCRM 스케줄링 알고리즘을 제시한다. 무선 환경에 따라 Uplink와 Downlink시 각각 다른 방법으로 실시간 멀티미디어 데이터 전송 스케줄링 정책을 적용하며 실시간 데이터와 비실시간 데이터의 QoS의 요구사항을 보장하고 불충분한 무선 자원을 공유분배를 위한 공평성 문제를 다룬다. 또한 VC(Virtual Control)를 BS(Base Station)에 두어 예약버퍼와 임의의 전송속도 pk를 사용하여 TCRM의 단점인 비실시간 데이터에 대한 비효율성 문제를 해결한다.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.321-323
• /
• 2015

Monitoring crane motion in real time is the first step to identifying and mitigating crane-related hazards on construction sites. However, no accurate and reliable crane motion capturing technique is available to serve this purpose. The objective of this research is to explore a method for real-time crane motion capturing and investigate an approach for assisting hazard detection. To achieve this goal, this research employed various techniques including: 1) a sensor-based method that accurately, reliably, and comprehensively captures crane motions in real-time; 2) computationally efficient algorithms for fusing and processing sensing data (e.g., distance, angle, acceleration) from different types of sensors; 3) an approach that integrates crane motion data with known as-is environment data to detect hazards associated with lifting tasks; and 4) a strategy that effectively presents crane operator with crane motion information and warn them with potential hazards. A prototype system was developed and tested on a real crane in a field environment. The results show that the system is able to continuously and accurately monitor crane motion in real-time.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.2588-2593
• /
• 2003

Any system has the possibility of an error occurrence. Even if trivial errors were occurred, the original system would be fatally affected by the occurring errors. Accordingly, the error detection must be demanded. In this paper, we developed a real-time error detection system would be able to apply to an electronic Jacquard system. A Jacquard is a machine, which controls warps while weaving textiles, for manufacturing patterned cloth. There are two types of mechanical and electronic Jacquard. An electronic Jacquard is better than a mechanical Jacquard in view of the productivity and realizability for weaving various cloths. Recent weaving industry is growing up increasingly due to the electronic Jacquard. But, the problem of wrong weaving from error data exists in the electronic Jacquard. In this research, a real-time error detection system for an electronic Jacquard is developed for detecting errors in an electronic Jacquard in real-time. The real-time system is constructed using PC-based embedded system architecture. The system detects the occurring errors in real-time by storing 1344 data transferred in serial from an electronic Jacquard into memory, and then by comparing synchronously 1344 data stored into memory with 1344 data in a design file before the next data would be transferred to the Jacquard for weaving. The information of detected errors are monitored to the screen and stored into a file in real-time as the outputs of the system. In this research, we solve the problem of wrong weaving through checking the weaving data and detecting the occurred errors of an electronic Jacquard in real-time.

• 디지털콘텐츠학회 논문지
• /
• 제10권4호
• /
• pp.649-657
• /
• 2009

일반적으로 초고속 네트워크에서 실행되는 분산 시스템의 데이터 전달처리 효율은 시스템 구조 및 데이터의 전달처리 시스템에 의존한다. 분산 환경을 이용한 실시간 분산 시뮬레이션 시스템은 데이터전달처리의 실시간성과 시스템의 신뢰성 보장을 위하여 데이터 전달처리 시스템에 의하여 요구된 성능을 만족하고자 하였다. 그러나 실시간 시뮬레이션 시스템에 적용된 클라이언트/서버 기반의 데이터 전달처리 시스템은 시스템의 안정성 및 시스템의 변경에 따른 확장성과 유지보수성 확보가 어려웠다. 따라서 기존의 데이터 전달처리 시스템의 문제점을 해결하기 위하여 새로운 데이터 전달처리 시스템이 필요하다. 본 논문에서는 기존의 실시간 시뮬레이션 시스템을 분석하여 시스템 개선방향을 제시하고, 시스템 확장성, 상호운용성, 재사용성 및 유지보수성을 위하여 소프트웨어 디자인 패턴을 적용한 새로운 실시간 데이터 전달처리 시스템을 제안한다.

• 한국군사과학기술학회지
• /
• 제8권4호
• /
• pp.24-31
• /
• 2005

This paper presents an implementation of a real-time multi-sensor data fusion algorithm for Flight Test Computer. The sensor data consist of positional information of the target from a radar, a GPS receiver and an INS. The data fusion algorithm is designed by the 21st order distributed Kalman Filter which is based on the PVA model with sensor bias states. A fault detection and correction logics are included in the algorithm for bad measurements and sensor faults. The statistical parameters for the states are obtained from Monte Carlo simulations and covariance analysis using test tracking data. The designed filter is verified by using real data both in post processing and real-time processing.

• 대한전기학회논문지
• /
• 제43권4호
• /
• pp.638-647
• /
• 1994

This paper describes the real time Hardware-In-the Loop Simulation(HILS) that is an efective tool for design, testing and performance evaluation of the guidanc eflight system. The real time HILS was performed by using a 3-axis flight motion simulator, real time computer, I/O system and flight control system hardware along with the assumed flight trajectory of the guidance flight system. Also, we proved the validity of the real time HILS is the guidance flight system by comparing its simulation results with the software simulation data and telemetry data.

• 한국컴퓨터정보학회논문지
• /
• 제21권5호
• /
• pp.57-64
• /
• 2016

In this paper, we propose the design of railway safety common data model to provide common transformation method for collecting data from railway facility fields to Real-time railway safety monitoring and control system. This common data model is divided into five abstract sub-models according to the characteristics of data such as 'StateInfoMessage', 'ControlMessage', 'RequestMessage', 'ResponseMessage' and 'ExtendedXXXMessage'. This kind of model structure allows diverse heterogeneous data acquisitions and its common conversion method to DDS (Data Distribution Service) format to share data to the sub-systems of Real-time railway safety monitoring and control system. This paper contains the design of common data model and its DDS Topic expression for DDS communication, and presents two kinds of data transformation case studied for verification of the model design.

• 한국항공운항학회지
• /
• 제20권4호
• /
• pp.39-44
• /
• 2012

This paper propose a transmission method for "Transportation system" that can decide precise position under wide area road traffic environment. For precise position detecting, central station collect multiple receiver station's satellite navigation data and generate correction information. In this process, we need efficient real time transmission method for satellite navigation message that has variable data size. We propose real time data transmission method. This real time transmission method offer efficient processing structure for multiple receiver station's satellite navigation message. This paper explains proposed real time transmission method and proofs this transmission method.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
• /
• pp.797-801
• /
• 2003

In this paper, a real-time communication method using a PICNET-NP (Plant Instrumentation and Control Network for Nuclear Power plant) is proposed with an analysis of the control network requirements of DCS (Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others.

• 한국해양공학회지
• /
• 제18권1호
• /
• pp.10-15
• /
• 2004

For effective conservation of the oceans and harbors, long-term and systematic development of the ocean and harbor monitoring system is essential. A monitoring system capable of real-time and accurate data acquisition is necessary for dealing with the level of contamination by situations, such as red tide and foods. This paper introduces an effective and economical real-time harbor environmental monitoring system that utilizes PCS wireless data communication technology. The monitoring system has various functions, such as multiple communication, TCP/IP protocol for wireless internet access, system time synchronization, and bi-directional communication between the measuring device and the server. The system has been implemented at Shinseondae harbor pier in Busan to validate the system's stability and effectiveness in data acquisition. The acquired real-time ocean and harbor environmental data is expected to have a large effect, when shared with the public through the Internet.