• Title/Summary/Keyword: Preemptive scheduling

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Implementation of Operating Software for Small Multi-Jointed Robots (소형 다관절로봇을 위한 운용 소프트웨어 구현)

  • Son, Hyun-Seung;Kim, Woo-Yeol;Kim, Young-Chul
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.946-951
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    • 2009
  • The small multi-jointed robots for most education are developed with the way of firmware. But the firmware may be very difficult to develop as gradually increasing throughputs and control routines. Due to limit of firmware we try to use on RTOS, but hard to adapt on the small multi-jointed robots. It would be hard to install RTOS into the small multi-jointed robots because of the size capacity of RTOS, and lack of libraries for control of the particular hardware. Moreover, even its RTOS with many functions causes its to make overheads scheduling, TCB (Task Control Block), and task states. Also to keep maintenance of RTOS, it is composed of components for the whole structure of my proposed RTOS. Additionally, We provided with libraries of servo motor and sensor control and developed RMS (Rate Montonic scheduler) to handle tasks on real time and reduce overheads. Therefore, It is possible to work the fixed priority and task preemptive way. We show one example of the multi-jointed robot installed with my proposed RTOS, which shows to obstacle avoidance and climbing up the slope.

Designing of Network based Tiny Ubiquitous Networked Systems (네트워크 기반의 소형 유비쿼터스 시스템의 개발)

  • Hwang, Kwang-Il;Eom, Doo-Seop
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.3
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    • pp.141-152
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    • 2007
  • In this paper, we present a network-oriented lightweight real-time system, which is composed of an event-driven operating system called the Embedded Lightweight Operating System (ELOS) and a generic multi hop ad hoc routing protocol suite. In the ELOS, a conditional preemptive FCFS scheduling method with a guaranteed time slot is designed for efficient real-time processing. For more elaborate configurations, we reinforce fault tolerance by supplementing semi-auto configuration using wireless agent nodes. The developed hardware platform is also introduced, which is a scalable prototype constructed using off-the-shelf components. In addition, in order to evaluate the performance of the proposed system, we developed a ubiquitous network test-bed on which several experiments with respect to various environments are conducted. The results show that the ELOS is considerably favorable for tiny ubiquitous networked systems with real-time constraints.

A Process Perspective Event-log Analysis Method for Airport BHS (Baggage Handling System) (공항 수하물 처리 시스템 이벤트 로그의 프로세스 관점 분석 방안 연구)

  • Park, Shin-nyum;Song, Minseok
    • The Journal of Bigdata
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    • v.5 no.1
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    • pp.181-188
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    • 2020
  • As the size of the airport terminal grows in line with the rapid growth of aviation passengers, the advanced baggage handling system that combines various data technologies has become an essential element in order to handle the baggage carried by passengers swiftly and accurately. Therefore, this study introduces the method of analyzing the baggage handling capacity of domestic airports through the latest data analysis methodology from the process point of view to advance the operation of the airport BHS and the main points based on event log data. By presenting an accurate load prediction method, it can lead to advanced BHS operation strategies in the future, such as the preemptive arrangement of resources and optimization of flight-carrousel scheduling. The data used in the analysis utilized the APIs that can be obtained by searching for "Korea Airports Corporation" in the public data portal. As a result of applying the method to the domestic airport BHS simulation model, it was possible to confirm a high level of predictive performance.

Simulation Modeling for Production Scheduling under Make-To-Order Production Environment : Focusing on the Flat Glass Production Environment (주문생산 방식의 생산계획 수립을 위한 시뮬레이션 모델 설계 : 판유리 제조 공정을 중심으로)

  • Choi, Yong-Hee;Hwang, Seung-June
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.1
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    • pp.64-73
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    • 2019
  • The manufacturing companies under Make-To-Order (MTO) production environment face highly variable requirements of the customers. It makes them difficult to establish preemptive production strategy through inventory management and demand forecasting. Therefore, the ability to establish an optimal production schedule that incorporates the various requirements of the customers is emphasized as the key success factor. In this study, we suggest a process of designing the simulation model for establishing production schedule and apply this model to the case of a flat glass processing company. The flat glass manufacturing industry is under MTO production environment. Academic research of flat glass industry is focused on minimizing the waste in the cutting process. In addition, in the practical view, the flat glass manufacturing companies tend to establish the production schedule based on the intuition of production manager and it results in failure of meeting the due date. Based on these findings, the case study aims to present the process of drawing up a production schedule through simulation modeling. The actual data of Korean flat glass processing company were used to make a monthly production schedule. To do this, five scenarios based on dispatching rules are considered and each scenario is evaluated by three key performance indicators for delivery compliance. We used B2MML (Business To Manufacturing Markup Language) schema for integrating manufacturing systems and simulations are carried out by using SIMIO simulation software. The results provide the basis for determining a suitable production schedule from the production manager's perspective.