• Title/Summary/Keyword: Real-time operation systems

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Practical and Verifiable C++ Dynamic Cast for Hard Real-Time Systems

  • Dechev, Damian;Mahapatra, Rabi;Stroustrup, Bjarne
    • Journal of Computing Science and Engineering
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    • v.2 no.4
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    • pp.375-393
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    • 2008
  • The dynamic cast operation allows flexibility in the design and use of data management facilities in object-oriented programs. Dynamic cast has an important role in the implementation of the Data Management Services (DMS) of the Mission Data System Project (MDS), the Jet Propulsion Laboratory's experimental work for providing a state-based and goal-oriented unified architecture for testing and development of mission software. DMS is responsible for the storage and transport of control and scientific data in a remote autonomous spacecraft. Like similar operators in other languages, the C++ dynamic cast operator does not provide the timing guarantees needed for hard real-time embedded systems. In a recent study, Gibbs and Stroustrup (G&S) devised a dynamic cast implementation strategy that guarantees fast constant-time performance. This paper presents the definition and application of a cosimulation framework to formally verify and evaluate the G&S fast dynamic casting scheme and its applicability in the Mission Data System DMS application. We describe the systematic process of model-based simulation and analysis that has led to performance improvement of the G&S algorithm's heuristics by about a factor of 2. In this work we introduce and apply a library for extracting semantic information from C++ source code that helps us deliver a practical and verifiable implementation of the fast dynamic casting algorithm.

An Expert System for Fault Section Diagnosis in Power Systems using the information including operating times of actuated relays and tripped circuit breakers (보호 계전기와 차단기의 동작 순서를 고려한 전력 시스템 사고 구간 진단을 위한 전문가 시스템)

  • Min, S.W.;Lee, S.H.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.125-127
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    • 2000
  • Multiple faults are hard to diagnose correctly because the operation of circuit breakers tripped by former fault changes the topology of power systems. The information including operating time of actuated relays and tripped circuit breakers is used for considering changes of the network topology in fault section diagnosis. This paper presents a method for fault section diagnosis using a set of matrices which represent changes of the network topology due to operation of circuit breakers. The proposed method uses fuzzy relation to cope with the unavoidable uncertainties imposed on fault section diagnosis of power systems. The inference executed by the proposed matrices provides the fault section candidates in the form of a matrix made up of the degree of membership. Experimental studies for real power systems reveal usefulness of the proposed technique to diagnose multiple faults.

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Real-Time Object Tracking and Segmentation Using Adaptive Color Snake Model

  • Seo Kap-Ho;Shin Jin-Ho;Kim Won;Lee Ju-Jang
    • International Journal of Control, Automation, and Systems
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    • v.4 no.2
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    • pp.236-246
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    • 2006
  • Motion tracking and object segmentation are the most fundamental and critical problems in vision tasks such as motion analysis. An active contour model, snake, was developed as a useful segmenting and tracking tool for rigid or non-rigid objects. In this paper, the development of new snake model called 'adaptive color snake model (ACSM)' for segmentation and tracking is introduced. The simple operation makes the algorithm runs in real-time. For robust tracking, the condensation algorithm was adopted to control the parameters of ACSM. The effectiveness of the ACSM is verified by appropriate simulations and experiments.

Monitoring System Design for the GPS/INS Integrated Navigation System (GPS/INS 통합 항법 시스템용 모니터링 시스템 설계)

  • 한상재;오상헌;황동환;이상정
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.3
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    • pp.242-250
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    • 2003
  • We propose the monitoring system scheme for the CPS/INS integrated navigation system. The design requirements of the monitoring system are suggested and the software scheme based on GUI is proposed. The proposed monitoring system consists of an I/O interface part, a navigation data display part, and a post-processing part. The I/O interface part is responsible for data communication between the monitoring system and a navigation computer unit. The navigation data display part provides various display methods to show the navigation data to user in real-time. The post-processing part collects the navigation data to analyze the performance of navigation system. The proposed monitoring system software was developed using the Visual C++ programming language and a van test was carried out to demonstrate the real-time operation of the monitoring system. The test result shows that the proposed monitoring system can be effectively applied to the CPS/INS integrated navigation system.

Vision Processing for Precision Autonomous Landing Approach of an Unmanned Helicopter (무인헬기의 정밀 자동착륙 접근을 위한 영상정보 처리)

  • Kim, Deok-Ryeol;Kim, Do-Myoung;Suk, Jin-Young
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.1
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    • pp.54-60
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    • 2009
  • In this paper, a precision landing approach is implemented based on real-time image processing. A full-scale landmark for automatic landing is used. canny edge detection method is applied to identify the outside quadrilateral while circular hough transform is used for the recognition of inside circle. Position information on the ground landmark is uplinked to the unmanned helicopter via ground control computer in real time so that the unmanned helicopter control the air vehicle for accurate landing approach. Ground test and a couple of flight tests for autonomous landing approach show that the image processing and automatic landing operation system have good performance for the landing approach phase at the altitude of $20m{\sim}1m$ above ground level.

An EEG Encryption Scheme for Authentication System based on Brain Wave (뇌파 기반의 인증시스템을 위한 EEG 암호화 기법)

  • Kim, Jung-Sook;Chung, Jang-Young
    • Journal of Korea Multimedia Society
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    • v.18 no.3
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    • pp.330-338
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    • 2015
  • Gradually increasing the value of the technology, the techniques of the various security systems to protect the core technology have been developed. The proposed security scheme, which uses both a Password and the various devices, is always open by malicious user. In order to solve that problem, the biometric authentication systems are introduced but they have a problem which is the secondary damage to the user. So, the authentication methods using EEG(Electroencephalography) signals were developed. However, the size of EEG signals is big and it cause a lot of problems for the real-time authentication. And the encryption method is necessary. In this paper, we proposed an efficient real-time authentication system applied encryption scheme with junk data using chaos map on the EEG signals.

Real-Time Network Traffic Monitoring System using SNMP (SNMP를 이용한 실시간 네트워크 트래픽 모니터링 시스템)

  • 박진호;정진욱
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.69-75
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    • 2002
  • In this paper, we propose the realtime network traffic monitoring system usin SNMP that can supported network and system operation, management, expansion, and design using network analysis and diagnosis to a network administrator. The proposed system consists of two parts: analysis server for collection and analysis of the network information, and supports real-time monitoring of network traffic, and client system shows user a graphical data that analyzed a returned result from the server. This system implements web-based technology using Java and contributes to enhance the effectiveness of network administrator's management.

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Research of Real-Time Remote Operation for Quality Improvement of the Air-compressor : Case Study of Reciprocating Air-compressor (공기압축기의 품질향상을 위한 실시간 원격 운영시스템 연구 : 왕복동형 공기압축기 대상으로)

  • Im, Sang-Don;Kim, Jong-Rae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.1
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    • pp.33-40
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    • 2014
  • Air compressor is an important facility with electric power in the industry. However, because of the noise and vibration of air compressor and is installed outside the building management difficulty. In this study, MCP (Micro Control Processor) to remote monitoring of the air compressor via the compressed air through improved quality and allows stable maintenance were designed. So, increase the productivity improvement of energy-saving effect can be obtained. Remote real-time information stored on your PC to manage air compressor equipment was higher reliability. Monitoring system is developed in this study was applied to embedded systems. It is easy to install air compressor, and low maintenance costs was to raise the economic impact.

Comparative Analysis of Operation Policies for a Zone Picking System (구역 피킹 시스템 운영 방안 비교 분석)

  • Mi Lim Lee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.47 no.2
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    • pp.190-197
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    • 2024
  • By the recent fast growth of e-commerce markets, it has been stimulated to study order picking systems to improve their efficiency in distribution centers. Many companies and researchers have been developed various types of order picking systems and pursued the corresponding optimal operation policies. However, the performances of the systems with the optimal policies often depend on the structures of the centers and the operation environments. Based on a simulation model that mimics a unique zone picking system operated by a real company in the Republic of Korea, this study compares several operation policies and finds the most appropriate order selection rule and worker assignment policy for the system. Under all scenarios considered in this study, simulation results show that it is recommendable to assign more efficient workers to the zones with heavier workload. It also shows that selecting the order with the maximum number of non-repeatedly visited zones from the order list provides the most consistent and stable performances with respect to flow time, makespan, and utilization of the system even under the scenario with the breakdown zones. On the other hand, selecting the order with the minimum ratio of penalty to the number of zones performs the worst in all scenarios considered.

Operation Results and Utility of Dynamic Pricing Response Control-Applied VRF System in Summer Season

  • Kim, Min-seok;Lee, Je-hyeon;Song, Young-hak
    • Architectural research
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    • v.19 no.3
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    • pp.71-77
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    • 2017
  • Dynamic pricing refers to a system in which a tariff varies, according to a level of charging and applied time depending on time change. The power billing system used in the Korean Electric Power Corporation (KEPCO) is based on time of use (TOU) pricing, which is one of the dynamic pricing systems. This paper aimed to determine the operational results of a variable refrigerant flow system, to which a new control algorithm was applied, in order to respond to dynamic pricing, in summer and the utility of the new control. To do this, real measured data was acquired from a VRF system installed in a building for educational purposes, where dynamic pricing was applied for about 100 days during summer time. At the maximum load operation time period in TOU, the new control minimized operation within the indoor comfort range, an increase in refrigerant evaporation temperature in the indoor unit and the number of revolutions in a compressor in the outdoor unit was limited. As a result, power usage was decreased by 11%, and the operational cost by 14.6%. Furthermore, measurement results using the Predicted Mean Vote (PMV) model, that represented satisfaction of thermal environment, showed that 82.8% to 90.4% of the occupants of the building were satisfied during operation when the new control was applied.