• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.187-189
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• 2007

In this paper, we present a model-driven approach for RTOS-based embedded software development and an automated tool that produces RTOS-specific code or RTOS-independent code. We define generic RTOS APIs (Application Programming Interface) that are not bound to any specific RTOS but provide most of typical RTOS services. Generic RTOS APIs can be used to describe application's RTOS-related behavior, The proposed API translator translates task code between C-code for specific RTOS and intermediate code using generic API. Also, the result can be extended to other RTOS's modifying XML transformation rule.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.3
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• pp.257-267
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• 2005

The real-time operating system(RTOS) simulator, one of the tools provided by RTOS development environment, allows users to develop and debug application programs even before the target hardware is ready. Thus, most of commercial RTOS development environments provide with RTOS simulator for the purpose. But they are implemented to simulate only functional aspects on a host system, so that it is not possible to estimate execution time of application programs on the target hardware. Since the real-time system has to complete program executions in predetermined time, the RTOS simulator that can estimate the execution time is yeW useful in the development phase. In this study, we develop a machine instruction-level RTOS simulator that is able to estimate execution time of application programs on a target hardware, and prove its functionality and accuracy by using test .programs.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.443-445
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• 2006

In this paper, we present a model-driven approach to RTOS(Real Time Operating System)-based embedded software development and an automated tool that can produce RTOS-specific code. we defined generic RTOS APIs(Application Programming Interface) that are not bound to any specific RTOS but can provide most of typical RTOS services. The generic RTOS APIs can be used as a means for describing application's RTOS-related behavior from design stage. Out tool, called Trans-PI, is able to produce specific 'C' code aimed at POSIX(Portable Operating System Interface for UNIX)-complicant RTOSs. And it is also configurable to target other RTOSs that do not conform to the POSIX standard.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.13-26
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• 2009

In this raper, We propose the alternative solution, RTOS-based system to replace the PLC 4hat has used the automation system for industrial processes. RTOS-based system is constructed the PC and RTOS as hardware and software. It overcomes the limit of PLC and guarantees the stability and reliability. Also, PC has better performance and cheaper than PLC when operating and constructing the system. For many manufactures, these benefits alone are all the reason they need to switch from PLC-based system to RTOS-based system. To use the RTOS-based System, the PLC program needs the conversion to the RTOS task. And how to transform is the most important issue. So, we propose conversion method through the system model. The system model defines the operation of each module as the task after the system divided into module. Because the system divided into modules can control, the performance and the functionality of system improve, and the system can deal with a problem easily when repairing and changing.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1325-1328
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• 2006

본 논문에서는 RTOS 기반 임베디드 소프트웨어 개발에 적합한 모델기반 방법론을 제안하고 이와 함께 개발된 자동코드생성 도구를 기술한다. 현재까지 알려진 대표적인 모델기반 방법론으로는 OMG (Object Management Group)의 MDA (Model-Driven Architecture)가 있으며, MDA 에서는 EJB, 웹서비스,.NET, 그리고 CORBA 와 같은 미들웨어 플랫폼을 대상으로 하는 응용 소프트웨어의 개발을 지원한다. 하지만, 통상적인 임베디드 시스템은 실시간성에 대한 요구조건은 물론 성능과 자원활용에 있어 많은 제약을 가짐에 따라 상당수의 임베디드 시스템은 미들웨어를 사용하지 않고 RTOS 상에서 직접 수행되도록 개발되고 있다. 이에 따라 본 연구에서는 MDA 방법론을 확장하여 플랫폼 의존적인 모델 (PSM, Platform Specific Model) 단계에서 추상화된 RTOS 행위를 표현할 수 있도록 추상 RTOS API (Generic RTOS API)를 정의하고, 아울러 추상화된 RTOS 행위를 자동으로 변환하여 C 코드를 생성해주는 도구인 TransPI 를 함께 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1301-1306
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• 2011

RTOS in the embedded system is a powerful tool for the design of multi-tasking. However, previous RTOS has large proportion in the MCU with limited memory. So it is difficult to apply RTOS. In this paper, I removed less frequently used features from the traditional RTOS, and designed lightweight RTOS that schedules and manages the resources with minimal code. I used techniques to obtain user memory using sharing stack, and to reduce the overhead at context. Considering ratio of kernel and applications, the RTOS designed in this paper is available on the MCU with more than 4KB of program memory.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.217-224
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• 2009

The traditional small educational multi-joint robots were developed on firmware. In these system's case, we cann't give a chance to educate good practices due on executing just robot's simple movements. But it may be possible for RTOS to control the elaborate movement of the robot with assembling each part on firmware. With this RTOS, we can enhance the efficiency of robot's movements, but too difficult to use the education as increasing the complexity of robot system. To solve the problem, we apply with Design pattern and Refactoring for the Education. Applying robot's design with Design pattern and Refactoring. There may be easily understand what and how to design RTOS for any level ones. We may easily change/upgrade RTOS for new system with this approach. This paper mentions to design RTOS with Design patterns and to apply RTOS's source code with Refactoring.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.133-137
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• 2018

Arduino is a small microcomputer that is used in a variety of industry fields and especially is widely used as an open source hardware IoT device. The multi-tasking method of Arduino is divided into super loop timing and RTOS thread method. The super loop timing method is simple and easy to understand. However, when one task is long, it affects the execution of the next task. In addition, RTOS threading has the advantage of being able to run without being influenced by other work time. However, Arduino, a small microcomputer, has a disadvantage in that, when the number of threads increases, the context switching time of the thread causes additional time not included in the super loop timing method have. In this paper, we use Arduino Uno R3 and FreeRTOS to analyze these different features, and the task for the experiment is to send 8000 digital signals to the built-in LED port. If two tasks of the same size are executed, the super loop method executes 3 ms faster than FreeRTOS multitasking. If multiple tasks are executed simultaneously, superloop type task is sequential execution and difference in execution time between first task and last task is large. FreeRTOS method can be executed concurrently, but execution time delay of about 30 ms occurs in context switching time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1020-1026
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• 2012

In this paper, we proposed a RTOS-based lighting control system to improve energy efficiency. This proposed system, real time process was designed to the specified division of the LED streetlight control module for the RTOS-based lighting control into three different tasks. The first task transmits LED lighting signal by measuring illuminance, and the second task transmits motion detecting signal using motion detector. In the third task, lighting control to LED was designed through passed control signal from other tasks The execution status was examined ports that are directly to the ATmega128 MCU for the verification of the system, and illuminance distribution and operating conditions were verified through LED street field test. The proposed RTOS-based lighting control system has brought improving system performance and also facilitate an addition of other functions, and it was possible to optimize energy saving by intelligent lighting pattern control.