• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.832-834
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• 2005

임베디드 시스템은 범용 컴퓨팅 시스템과 달리 자신을 포함하고 있는 기기에 부과된 특정 목적의 컴퓨팅 작업만을 수행한다. 이 시스템을 제어하기 위해서 운영체제가 필요로 하며, 임베디드 환경에서는 신뢰성과 정확성을 요하는 부분이 많기 때문에 실시간 운영체제를 필요로 한다. Real-Time kernel을 기반으로 하는 MicroC/OS-II는 수많은 용도로 사용되고 있지만 task 사용에 한계가 있다. 이 논문에서 제안하는 스케줄링은 task의 생성 수를 늘려주지만, 이 경우 task간의 우선순위 설정이 어려워진다. 이 문제 해결을 위해서 task들의 우선순위 결정은 deadline을 이용하여 3레벨로 나눈다. 3레벨로 나누어지면 task의 수가 증가해도 개발자는 task들을 레벨에 맞게 설정하면 task 관리로 인하여 생기는 문제를 줄일 수 있으며, 효율적인 스케줄링을 가능하게 한다.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.223-223
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• 2000

Embedded system area has brought an innovation and has been spread rapidly by the growth of the Internet, wireless telephony and multimedia recently. Many embedded systems are required to be real-time systems in that it needs multi-tasking and priority based scheduling. This paper introduces a real-time system that was developed with web server ability for control and monitoring system employing a real-time operating system. It discusses the design model, structure, and applications of web server system. We used SNDS100 board which has a 32-bit RISC microcontroller of ARM7TDMI core as a hardware platform. MicroC/OS kernel was used as Real-time operating system that supports a preemptive and multitasking functions. We developed a hierarhchical control and monitoring system that not only reduced system and management costs, but also enhanced reusability and portability.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.94-96
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• 2001

저전력 시스템에 대한 연구는 회로 수준에서부터 응용 소프트웨어 수준에 이르기까지 다양한 각도에서 이루어지고 있다. 본 연구에서 는 특히 운영 체제 수준, 즉 $\mu$C/OS-II(MicroC/OS-II) 커널 코드의 다양한 함수들에 대한 에너지 소비값을 추출하며 이 결과를 바탕으로 운영체재의 각 모듈별 에너지 소비를 분석한다. 이를 위하여 ARM7TDMI 마이크로 콘트롤러를 이용하여 제작된 시스템에 $\mu$C/OS-IIl 운영체제를 이식하고 SES(SNU Energy Scanner)툴을 이용하여 수행된 운영체제 코드의 각 모듈 즉 태스크 관리, 인터럽트 처리, IPC등에 대한 에너지 소비를 얻고 이 결과를 분석한다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.3
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• pp.182-187
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• 2004

In this paper, we propose a PC based distributed controller for a two axis convey table using real-time micro-kernel. PC, Windows program, gives an easy way to implement wealthy GUI and micro-kernel, ${\mu}$C/OS-II, provides a real-time capability to control devices. We built a real-time distributed control system using ${\mu}$C/OS-II kernel which needs to process the tasks for two motors within the desired time to synchronize the motion. We used both semaphore and message mail box for synchronization. Unlike the previous study where we used step motors for the actuator of two axes convey table, we rebuilt the convey table with DC motors and the dedicated position servo which had built in out lab, and then we implemented a realtime distributed control system by putting the micro-kernel into between PC and position servo. Moreover we developed the PC based graphic user interfaces for generating planar drawing image control. Experimental results also presented to show the Proposed control system is useful.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.348-357
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• 2009

The purpose of this study was to evaluate the micro-tensile bond strength (${\mu}TBS$) of four luting resin to regional dentin of human primary teeth. Dentin from non-carious primary molars were prepared from different regions (s, superficial dentin; d, deep dentin; c, cervical dentin), and divided into groups based on anatomical locations and types of luting resins (Scotchbond Multi-purpose : SB ; One-Step : OS ; AdheSE Bond : ASE ; G-Bond : GB) : SB-s, SB-d, SB-c; OS-s, OS-d, OS-c; ASE-s, ASE-d, ASE-c ; GB-s, GB-d, GB-c. Luting resins were used according to the manufacturers' instructions, to bond $Light-Core^{TM}$ Core Build-Up Composite) to the exposed dentin specimens in the light-curing mode. After storage for 1 day, ${\mu}TBS$ was tested at a cross-head speed of 1 mm/min. Data were analyzed with T-test and two-way ANOVA. The bonding interface and fractography analyses were performed with SEM. The results were as follows : 1. ${\mu}TBS$ to superficial dentin was significantly higher than to deep dentin for SB(p<0.05). But there were no significant differences in regional ${\mu}TBS$ among OS, ASE, GB(p>0.05). 2. There were no significant differences in ${\mu}TBS$ to superficial dentin among each groups. But, in deep dentin, ${\mu}TBS$ of SB-d was significantly lower than those of OS-d, ASE-d, and GB-d(p<0.05). ${\mu}TBS$ of OS-d was significantly higher than those of GB-d(p<0.05), but there were no significant differences in ${\mu}TBS$ of ASEd. There were no significant differences among ${\mu}TBS$ of ASE-d, OS-d, and GB-d.

• The Journal of the Korea Contents Association
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• v.10 no.1
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• pp.59-67
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• 2010

Laboratory works for embedded system courses are usually performed with hardware based experimental kits that equipped with an embedded board and software development tools. Hardware-based kits have demerits such as high initial setup cost, burdensome maintenance, inadaptability to industry evolution, and restricted educational outcomes. This paper proposes using virtual experimental environments to overcome the demerits of hardware-based kits and describes the design and implementation of a simulation-based virtual experimental kit. With ARM's ARMulator, we developed the kit by adding hardware IPs and user interface modules for peripherals. The developed kit is verified with an experimental program that uses all the augmented software modules. We also ported MicroC/OS-II on the virtual experimental kit for real-time OS experiments.

• Journal of Software Assessment and Valuation
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• v.16 no.1
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• pp.65-79
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• 2020

As Programmable Logic Controllers (PLCs), popular components in industrial control systems (ICS), are incorporated with the technologies such as micro-controllers, real-time operating systems, and communication capabilities. As the latest PLCs have been connected to the Internet, they are becoming a main target of cyber threats. This paper proposes two sanitizers that improve the security of uC/OS-II based firmware for a PLC. That is, we devise BU sanitizer for detecting out-of-bounds accesses to buffers and UaF sanitizer for fixing use-after-free bugs in the firmware. They can sanitize the binary firmware image generated in a desktop PC before downloading it to the PLC. The BU sanitizer can also detect the violation of control flow integrity using both call graph and symbols of functions in the firmware image. We have implemented the proposed two sanitizers as a prototype system on a PLC running uC/OS-II and demonstrated the effectiveness of them by performing experiments as well as comparing them with the existing sanitizers. These findings can be used to detect and mitigate unintended vulnerabilities during the firmware development phase.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.559-565
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• 2010

In this paper, we present a transformation method of source code from a POSIX (Portable Operating System Interface) based source code into an OSEK/VDX (Offene Systeme und deren Schnittstellen fur die Elektronik in Kraftfahrzeugen/Vehicle Distributed eXecutive) source code. As the electronic parts of automobile systems increase, the use of embedded software in automobile systems is also growing. Accordingly, many electronic systems are designed in automobile system with OSEK/VDX. Otherwise, one of the major problems of embedded software would be portability to other OS's. To enhance the portability and interoperability of embedded software, we propose a source code transformation method from POSIX to OSEK/VDX based on API (Application Programming Interface) translation method. Considering the characteristics of the OSEK/VDX which uses OIL (OSEK/VDX Implementation Language) standard, transformation process is performed with source code transformation and OIL code generation. For the validity of the proposed method, the transformation experiment is given using Micro-C OS II and OSEK/VDX with XC167CI micro-controller.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.45-46
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• 2009

최근에 다기능 복합화되는 임베디드 시스템을 위한 가상화 연구가 활발하다. 본 논문에서는 L4 마이크로커널을 기반으로 한 실시간 운영체제 MicroC/OS-II 가상화를 위한 L4 환경에서의 전체 구성, 인터럽트 핸들링, 게스트 운영체제 초기화 과정의 설계에 대해 기술한다.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.162-165
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• 2005

전력연구원은 고속의 DSP TMS320C33를 이용하여 실시간 정지형 계통연계 발전기 시뮬레이터를 개발하였다. 특히 소프트웨어로는 MicroC-OS를 이용하였으며 제어주기는 2500Hz이상으로 설계되었다. 실제 발전소에서 상업 운전되고 있는 여자시스템을 대상으로 하여 시뮬레이터 시험을 완료하였다.