Authors: 송태효, 박대동, 박지용, 홍성수
Conference: 대한전자공학회 추계 학술대회
Status: Published
Date: 2008. 11
Full text:
Abstract:
SCA(Software Communications Architecture) is the standard platform for SDR(Software Defined Radio) systems and also supports multi-mode SDR systems. However, since the SCA specification requires a number of file copy operations during the mode switching, the current implementations of SCA experience an unacceptable mode switching performance. In this
paper, we propose a file system mapping mechanism to increase the mode switching performance while following SCA specifications.
Posted by 봄날병아리
Authors: 박지용, 임진택, 홍성수
Conference: 대한전자공학회 추계 학술대회
Status: Published
Date: 2008. 11
Full text:
Abstract:
Software Communications Architecture (SCA) is a de facto standard for military Software
Defined Radio (SDR) systems. It greatly increases flexibility and portability of waveform software. However, building a SDR system using SCA has been considered as a difficult task due to the complexity and ambiguity of the SCA specification. In order to resolve this, we
present an effective method of building SDR systems using SCA core framework and show
the detailed roles of hardware and software engineers in building a system.
Posted by 봄날병아리
Authors: 박지용, 송태효, 홍성수
Conference: 대한전자공학회 추계 학술대회
Status: Published
Date: 2008. 11
Full text:
Abstract:
Software Communications Architecture(SCA) provides mechanisms for installing, creating,
running and releasing waveform applications in Software Define Radio(SDR) systems. When we were implementing SCA in C++, we have found that memory leaks can occur while a waveform is being released. In this paper, we analyze the cause of the problem and present three viablesolutions using clean-up threads.
Posted by 봄날병아리
Authors: 임진택, 금한홍, 박지용, 홍성수
Conference: 대한전자공학회 추계 학술대회
Status: Published
Date: 2008. 11
Full text:
Abstract:
The OSEK OS is the standard RTOS in the automotive domain. However, the implementation
of the OSEK OS must take memory consumption into account in order to use memory efficiently. To that end, we have designed specific kernel mechanisms to minimize memory usage in the OSEK OS.
Posted by 봄날병아리
Authors: Jiyong Park and Seongsoo Hong
Conference: The 24th Annual ACM Symposium on Applied Computing (SAC)
Status: Accepted
Date: 2009. 03
Full text:
Abstract:
Aspect-oriented programming (AOP) has been successful in modularizing crosscutting concerns in complex software systems. In this paper, we present our aspect-oriented approach to building a highly customizable embedded operating system. This is a challenging task since embedded operating systems consist of intertwined concerns often implemented using a mixture of multiple programming languages including an assembly language. Furthermore, they often contain hand-optimized code that makes clear modularization extremely difficult. We provide a two-step approach that addresses these difficulties. First, we devised an aspect-oriented programming environment AOX (Aspect-Oriented eXtension). It supports both modularization and customization of complex software via a set of aspect-oriented mechanisms. AOX extends existing approaches in the sense that it is entirely programming language independent and provides fine-grained joinpoints. Second, using AOX, we built a customizable embedded operating system we call the HEART OS. It is highly configurable and very user-friendly. AOX has been implemented and integrated into the Eclipse IDE as a plug-in module. The HEART OS has also been implemented and ported to the XScale and x86 platforms. Our experience with AOX in building the HEART OS was very positive.
Posted by 봄날병아리
Authors: Stanislav A. Belogolov, Jiyong Park and Seongsoo Hong
Conference: The 14th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA)
Status: Published
Date: 2008. 08
Full text:
Abstract:
In an attempt to substitute NOR flash with NAND flash and provide more memory to applications, embedded systems have to use demand paging. However, demand paging drastically degrades performance when the page faults rate is high. Prefetching has been known as a common remedy for the page fault overhead. Although many prefetching mechanisms have been proposed, they are efficient only for specific page access patterns. Others tend to be either too naïve to provide impressive results or
too difficult to implement. We propose the scheduler-assisted prefetching mechanism which does not have such fundamental defects. As a proof of concept, this mechanism was completely implemented in Linux. We also have conducted a series of experiments to show the effectiveness of our approach. The experimental results showed a significant improvement: the number of the major page faults and the scheduling latency decreased by 30% and 51%, respectively.performance characteristics to a raw socket-based communication implementation and the Lightweight-CCM implementation by MicoCCM.
Posted by 봄날병아리
Authors: Chetan Raj, Jiyong Park and Seongsoo Hong
Conference: The 14th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA)
Status: Published
Date: 2008. 08
Full text:
Abstract:
A component framework plays an important role in CBSD as it determines how software components are developed, packaged, assembled and deployed. A desirable component framework for developing diverse cross-domain embedded applications should meet such requirements as (1) lightweight on memory use, (2) integrated task execution model, (3) fast inter-component communication, (4) support for distributed processing, and (5) transparency from underlying communication middleware. Although current embedded system component frameworks address some of the above requirements, they fail to meet all of them taken together. We thus propose a new embedded system component framework called CREAM (Component-based Remote-communicating Embedded Application Model). It achieves these goals by using build-time code generation, explicit control of task creation and execution in the component framework, static analysis of component composition to generate efficient component binding, and abstraction of the component’s application logic from the communication middleware. We have implemented the CREAM component framework and conducted a series of experiments to compare its performance characteristics to a raw socket-based communication implementation and the Lightweight-CCM implementation by MicoCCM.
Posted by 봄날병아리
Authors: Xiaolin Xi, Jiyong Park, Jiakun Liu and Seongsoo Hong
Conference: International Conference on Software Engineering and Knowledge Engineering (SEKE)
Status: Accepted
Date: 2008. 07 (scheduled)
Full text:
Abstract:
In component-based software development, component selection is a critical step since the selected components considerably affect the system quality and the integration cost. Traditionally, the selection has been done in an ad-hoc manner, which takes a long time and does not guarantee the quality of the resultant system. These problems become more significant as either the complexity of a system or the size of component repositories increase. Although a number of selection methods have been proposed, they cannot ensure the suitability of selected components on system-level and fail to consider mixed-granularity components. We present a goal-oriented mixed-granularity (GOMG) component selection method to solve these problems. It adopts a hierarchical goal tree to provide options to use components in different granularities. Also, it exploits a hierarchical evaluation method that systematically measures the appropriateness of component sets on the system level. We have conducted a case study of building a composite SoC CAD tool. The component repository consisted of 250 components that varied considerably in both granularity and performance. The results show that our GOMG method yields a better aggregated score than the existing method by 33% and reduces the time consumed on the selection by 73%.
Posted by 봄날병아리
Authors: 임진택, 박지용, 송태효, 홍성수
Conference: 한국 자동차 공학회 (KSAE)
Status: Accepted
Date: 2008. 03
Full text:
Abstract:
Nowadays, automotive software system is becoming increasingly complicated. This complexity can be managed by the use of a reliable operating system. Moreover, mass production is the one of the characteristics of automotive industry. Therefore, reducing the physical resources used by the automotive software is important to cut costs. This situation can be appropriately solved by OSEK OS. OSEK is a real-time operating system specially designed for automotive software systems. One of the main design goals of OSEK is to reduce resource usage. In this paper, we analyze the properties of OSEK OS such as task model, conformance class and development process with OSEK Implementation Language (OIL). We then propose our implementation of OSEK OS with special focus on optimizing the memory usage.
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Authors: Jonghun Yoo, Jiyong Park and Seongsoo Hong
Conference: IEEE Transactions on Consumer Electronics (TECS)
Status: Published
Date: 2008. 02
Full text:
Abstract:
Bridging IEEE 1394 buses is becoming important since it can be used to provide wireless connectivity among 1394 devices. Unfortunately, existing bridge mechanisms, such as the IEEE 1394.1 bridge and the transparent bridge, have practical limitations. The former does not support interoperability with legacy 1394 devices and the latter requires a new hardware chipset for bridge implementation. We thus propose a new bridge mechanism called a mirroring bridge to overcome these limitations. It supports interoperability with legacy 1394 devices by emulating remote nodes inside a bridge and via packet address translation that can be implemented through software. We have implemented the proposed bridge mechanism and have succeeded in interconnecting legacy 1394 devices over an experimental WiMedia UWB network. The experimental result showed that the average throughput of the mirroring bridge is 188.7 Mbps, which is 94.4% of the maximum throughput of the UWB chipset used.
Posted by 봄날병아리
Authors: 박지용, 유종훈, 홍성수
Conference: 자동차기술개발통합 워크숍
Status: Published
Date: 2007. 9
Full text:
Abstract:
AUTOSAR is the middleware specialized for the automotive environment. It allows software running on top of AUTOSAR to be composed of independently developed components to improve reusability. Nevertheless, the adoption of AUTOSAR is not yet widespread mainly due to two reasons. First, developers need an extensive body of background knowledge in software engineering to effectively utilize it. Second, many developers in the automotive industry have a groundless concern that the communication cost among components in AUTOSAR is excessively high. In this paper, in order to overcome these two problems, we analyze the communication and execution models of AUTOSAR components. In the communication model, we explain how independently developed components are assembled and communicate with each other. In the execution model, we analyze mapping between components and tasks.
Posted by 봄날병아리
Authors: Jonghun Yoo, Jiyong Park and Seongsoo Hong
Conference: IEEE International Conference on Consumer Electronics (ICCE)
Status: Published
Date: 2007
Full text:
Abstract:
Bridging IEEE 1394 buses is becoming important since it enables wireless connectivity. Unfortunately, existing bridging schemes such as the IEEE 1394.1 and transparent bridges have practical limitations. The former does not support interoperability with legacy 1394 devices and the latter requires a new hardware chipset for bridge implementation. We thus propose a mirroring bridging scheme to overcome these limitations. It supports interoperability with legacy 1394 devices by emulating remote nodes inside a bridge and via packet address translation that can be implemented in software. We have successfully implemented the mirroring bridge scheme and conducted extensive experiments. The average throughput of the mirroring bridge was 188.7 Mbps that is 99.3% of the maximum throughput of the UWB network.
Posted by 봄날병아리
2007-03-20: Ongoing Research
2007-01-09: Formal Description of AOX
2006-12-21: Building a Customizable Embedded Operating System with Fine-Grained Joinpoints Using the AOX Programming Environment
2006-11-08: Building a Customizable Embedded Operating System with Fine-Grained Joinpoints Using the AOX Programming Environment
2006-06-09: Wombat: A Portable User-Mode Linux for Embedded Systems
2006-04-07: L4Linux
2006-03-17: Design of HEART
2005-12-12: Generalizing The Network Performance Interference Problem
2005-09-26: Operating System Design with AOX
2005-07-07: Feature Interactions in MaCE
2005-05-06: Modularization and Customization Environment (MaCE)
2005-02-28: Optimizing J2ME Applications with Cross-Module Method Inlining
2005-02-22: Preventing Interrupt Overload
2005-02-22: Preventing Network Performance Interference of Bidirectional TCP Traffic with Packet Scheduling in A Home Network Gateway Using An Asymmetric Link
2004-11-26: Customization of Java Library Classes Using Type Constraints and Profile Information
2004-08-09: Extracting Features from uC/OS II
2004-06-01: Customizing Operating Systems
2004-03-16: MaCE: Aspect Oriented Programming Environment for Mudularizing and Configuring Complex Software Systems
2003-12-31: Related Work of My Research Area - Separation of Concerns -
2003-11-11: Implementing FOP Framework
2003-09-24: FOP Framework
2003-07-15: Modeling Aspect and Weaving
2003-05-21: Aspects at the Design Level
2003-04-16: Customizable Operating Systems with Aspect-Oriented Programming
2003-02-05: XIP - eXecute In Place
2002-12-18: Chord: A Scalable Peer-To-Peer Lookup Service for Internet Applications
2002-07-22: Type-Safe Delegation for Run-Time Component Adaptation
2002-07-12: Glossary Related to Component
2002-06-25: CBOS Development Environment Specification
2002-05-08: A Survey of Configurable, Component-Based Operating Systems for Embedded Applications
2002-03-11: Key Exchange in IPSec: Analysis of IKE
2002-02-18: JXTA: A Network Programming Environment
Posted by 봄날병아리
Authors: 유우석, 박지용, 홍성수
Conference: 자동차기술개발통합 워크숍
Status: Published
Date: 2006.8
Full text:
Abstract:
To handle distributed hard real-time and safety-critical characteristics of automotive software, real-time operating systems, middleware, and fault-tolerance mechanisms are becoming widely used in automotive industries. In this paper, we give our research results on analyzing existing technologies in preparation of developing our own automotive software platform. OSEK and AUTOSAR are the representative real-time operating system and middleware for automobile. Since they are generated according to the system specifications, they are very lightweight and optimized while enabling component-based development of automotive software. We also categorize various fault-tolerance technologies. Among them, we especially concentrate on recovery block and N-version
programming.
Posted by 봄날병아리
Authors: 유우석, 박지용, 유종훈, 김세화, 홍성수
Conference: 한국자동차공학회 워크숍 및 심포지엄 논문집 (전기전자, ITS 부문 심포지움)
Status: Published
Date: 2006.8
Full text:
Abstract:
To overcome the ever increasing complexity of automotive software, it is inevitable to employ a standardized software platform. AUTOSAR is the well known automotive software platform from the European automotive industry. It provides a standardized communication layer called Run-Time Environment (RTE) that simplifies communications among automotive software modules distributed on in-vehicle networks. It also provides essential services that encapsulate the heterogeneity of in-vehicle hardware and system software, such as operating systems and ECU/microcontroller abstraction modules. These enable programmers to concentrate on implementing their own business logic. In this paper, we present the key concepts, software architecture, and development process of AUTOSAR-based automotive software systems.
Posted by 봄날병아리
Authors: 홍성수,박지용, 유우석
Conference: 대한정밀공학회 학회지
Status: Published
Date: 2006.9
Full text:
Abstract:
None
Posted by 봄날병아리
Authors: 박지용, 홍성수
Conference: 대한전자공학회 하계종합학술대회
Status: Published
Date: 2006.6
Full text:
Abstract:
In this paper, we present an RTOS named HEART (Highly Expandable AOP-based Real-Time operating system). It is modularized into a single base and multiple optional features. The base implements a core functionality and each feature implements a specific functionality of RTOS such as interrupt nesting, multithreading, inter-thread communication, and etc. Users can customize HEART just by selecting needed features. Then a specialized version of HEART is automatically generated. We argue that HEART enables the rapid construction of optimized and application-specific RTOSes for diverse embedded systems.
Posted by 봄날병아리
Authors: 박지용, 김세화, 최동호, 홍성수
Conference: 자동차공학회 춘계 학술대회
Status: Published
Date: 2006.6
Full text:
Abstract:
Automotive software is inherently distributed and possesses fault-tolerance and real-time requirements. Middleware is a software layer that can handle these intrinsic complexities of automotive systems thus enables programmers to concentrate on their own logic. This paper presents a middleware architecture specially designed for automotive software. It is based on message-oriented middleware (MOM) so that it can be efficiently implemented on
automotive network hardware. It incorporates many features required in automobiles such as real-time guarantee, fault-tolerance, and existence of a global time base.
Posted by 봄날병아리
Authors: 김세화, 박지용, 홍성수
Conference: 정보처리학회논문지: 컴퓨팅의 실제 제 12-D권 제 7호, pp. 1049-1064
Status: Published
Date: 2005.12
Full text:
Abstract:
내장형 시스템이 제공하는 기능이 다양해 지고 그 구조가 복잡해짐에 따라, 이들 시스템을 설계하는 데에 객체 지향 설계 방법론이 널리 사용되고 있다. 객체로 설계된 시스템을 대상 하드웨어에서 수행시키기 위해서는 객체들로부터 태스크 집합을 유도해야 하는데, 여기에 몇 개의 태스크가 존재하며 각 태스크가 어떤 객체들로 도착한 어떤 이벤트를 처리하느냐에 따라 시스템의 응답성이 크게 좌우된다. 그럼에도 불구하고 객체와 태스크의 상이함 때문에 최적의 태스크 집합을 유도하는 것은 매우 어려운 일이며, 그로 인해 지금까지는 여러 태스크 집합을 반복적으로 시도해 보는 것이 보편적인 방법이었다. 본 논문에서는 이 문제를 해결하는 Scenario-based Implementation Synthesis Architecture(SISA)를 제안한다. SISA는 객체로 설계된 시스템에서 태스크 집합을 유도하는 방법, 그리고 이를 지원하는 개발 도구와 런타임 시스템 아키텍처를 총칭한다. 이를 이용하여 개발된 시스템은 가능한 적은 개수의 태스크들로 이루어져 있으면서도 시스템의 각 이벤트에 대한 응답 시간이 최소임이 보장된다. 우리는 UML 2.0을 모델링 언어로 사용하는 개발도구인 RoseRT를 확장하여 SISA를 구현했으며, 기 개발된 산업용 PBX(사설 교환기) 시스템에 이를 적용했다. 이 시스템의 성능 평가 결과, 지금까지 알려진 최선의 태스크 유도 방식을 이용하여 개발되었을 때에 비해, 시스템의 최대 응답 시간이 평균 30.3% 단축된다는 것을 확인할 수 있었다.
Posted by 봄날병아리
Authors: 홍성수, 이재수, 박지용
Conference: SK Telecommunications Review 제 15권 4호, pp. 612-625
Status: Published
Date: 2005.8
Full text:
Abstract:
내장형 시스템들은 통산 자원의 극심한 제약을 받는데, 이것이 개발자에게 심각한 어려움이 되고 있다. 최근 반도체 집적 기술이 발달하여 메모리 장치의 가격이 급격히 하락하였음에도 불구하고 시스템 메모리는 휴대 전화와 같은 내장형 시스템에 있어 여전히 매우 귀한 자원의 하나이다. 공유 라이브러리 기법은 이러한 시스템 메모리의 사용량을 효과적으로 줄일 수 있는 대표적인 기술이다. 그런데 기존의 공유 라이브러리 기법들이 MMU의 지원을 필요로 하는데 반해서, 많은 내장형 시스템에는 MMU가 장착되어 있지 않다. 본 논문에서는 MMU가 없는 내장형 시스템에서의 공유 라이브러리를 지원하기 위한 새로운 기법을 제안한다. 이 기법은 준 정적 공유 라이브러리라고 불리는데, 이의 가장 큰 특징은 전역 심볼들이 링킹 시에는 논리 주소에 바인딩되고, 적재 시에 실제 물리 주소가 바인딩된다는 점이다. 이 기법을 구현하기 위해서 우리는 데이터 영역 베이스 레지스터와 데이터 영역 베이스 테이블을 고안하고, 이들과 함께 컴파일러를 확장하여 MMU의 메모리 사상 기능을 소프트웨어적으로 구현하였다. 본 논문에서 제안된 기법은 MMU가 없는 uClinux 기반의 내장형 시스템에 적용되었다. 우리는 이 시스템 위에서 메모리 사용량과 성능 변화를 측정하기 위한 다수의 실험을 수행하여, 제안된 기법이 메모리 사용량을 줄이는데 매우 효과적임을 보였다. 실험의 결과로 준 정적 공유 라이브러리를 사용하면 플래시 메모리 사용량이 약 35% 감소하며, RAM 사용량은 약 10% 가량 감소한다. 이에 비해 구현된 기법은 단지 4% 미만의 성능 저하를 초래한다.
Posted by 봄날병아리
Authors: 박지용, 이재수, 홍성수, 김동환, 장동은
Conference: 2003 SoC Design Conference, pp. 722-727
Status: Published
Date: 2003.11
Full text:
Abstract:
Embedded systems are quite often subject to severe resource constraints, and this makes it extremely challenging to develop embedded systems. Despite of rapid decrease in the price of solid state memory devices, system memory is still a very precious resource in embedded system development. In this paper, we present two effective techniques to significantly reduce the memory requirement of MMU-less uClinux based embedded systems. They are statically linked dynamically shared libraries and execute-inplace
(XIP). Without MMU, it is extremely difficult to support these techniques, and we present our solution approaches in detail. The end result of applying them is drastic - 50% of reduction in memory requirement. Even though they are applied to uClinux based embedded systems, they can be used for any MMU-less real-time operating systems.
Posted by 봄날병아리
Authors: Jiyong Park and Seongsoo Hong
Conference: 2003 SoC Design Conference, pp. 966-970
Status: Published
Date: 2003.11
Full text:
Abstract:
본 논문에서는 실시간 운영체제(RTOS)를 모듈화 하기 위하여 그래픽 기반의 Aspect-Oriented Programming (AOP) 프레임워크를 제시한다. 기존의 컴포넌트, 객체 지향 방법론, 그리고 최근의 AOP들은 RTOS와 같이 많은 기능 들이 복잡하게 연관된 소프트웨어를 모듈화 하는 데는 적합하지 않았다. 본 논문의 새로운 AOP 프레임워크는 다음과 같은 특징을 가지고 있다. 첫째, 클래스나 메소드의 단위를 넘어서서 구현되는 기능들이 어떻게 aspect로 모듈화 되 는지를 시각적으로 보여준다. 또한 기존의 AOP와 같이 여러 aspect들을 이리저리 옮겨 다닐 필요 없이, 한 곳에서 코 드가 어떤 순서로 수행될 지 알 수 있도록 해 준다. 둘째, 코드를 삽입할 위치를 지정하는 단위를 메소드 단위보다 더 세밀하게 하여 메소드의 수행 중간에 특정 aspect를 위한 코드를 삽입할 수 있도록 하였다. 그래서 하나의 메소드에 여러 aspect가 복잡하게 관여하는 경우가 많은 RTOS를 디자인 할 때 특히 유리하다.
Posted by 봄날병아리
Authors: 박지용, 김세화, 홍성수
Conference: 한국정보과학회 제30회 추계학술발표회, pp. 307-309
Status: Published
Date: 2003.10
Full text:
Abstract:
본 논문에서는 실시간 운영체제(RTOS)를 모듈화 하기 위하여 그래픽 기반의 Aspect-Oriented Programming (AOP) 프레임워크를 제시한다. 기존의 컴포넌트, 객체 지향 방법론, 그리고 최근의 AOP들은 RTOS와 같이 많은 기능 들이 복잡하게 연관된 소프트웨어를 모듈화 하는 데는 적합하지 않았다. 본 논문의 새로운 AOP 프레임워크는 다음과 같은 특징을 가지고 있다. 첫째, 클래스나 메소드의 단위를 넘어서서 구현되는 기능들이 어떻게 aspect로 모듈화 되 는지를 시각적으로 보여준다. 또한 기존의 AOP와 같이 여러 aspect들을 이리저리 옮겨 다닐 필요 없이, 한 곳에서 코 드가 어떤 순서로 수행될 지 알 수 있도록 해 준다. 둘째, 코드를 삽입할 위치를 지정하는 단위를 메소드 단위보다 더 세밀하게 하여 메소드의 수행 중간에 특정 aspect를 위한 코드를 삽입할 수 있도록 하였다. 그래서 하나의 메소드에 여러 aspect가 복잡하게 관여하는 경우가 많은 RTOS를 디자인 할 때 특히 유리하다.
Posted by 봄날병아리
Authors: Jiyong Park and Seongsoo Hong
Conference: IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA)
Status: Published
Date: August, 2007
Full text:
Abstract:
In network-enabled consumer electronics development, much of the time and effort is spent analyzing and solving network performance problems. In this paper, we define an instance of such problems discovered while developing a commercial home network gateway. We then analyze its cause and propose a solution mechanism. Our home network gateway uses an asymmetric link (ADSL) and suffers from an undesirable phenomenon where downlink traffic interferes with upload speed. We call this phenomenon the network performance interference problem. While this problem can easily be confused with receive livelock caused by packet contention at the input queue, we find that this is not the case. By performing extensive experiments and analysis, we reveal that our problem is caused by packet contention at the output queue and certain intrinsic
characteristics of TCP. We devise an ACK-separation queuing mechanism for this problem and implement it in the home network gateway. Our experiments show that it effectively solves the problem.
Posted by 봄날병아리
Authors: Jiyong Park, Saehwa Kim, Wooseok Yoo, and Seongsoo Hong
Conference: SICE-ICCAS Internation Joint Conference, pp. 694-698
Status: Published
Date: October, 2006
Full text:
Abstract:
Automotive software development poses a great deal of challenges to automotive anufacturers since an automobile is inherently distributed and subject to fault-tolerance and real-time requirements. Middleware is a software layer that can handle the intrinsic complexities of distributed systems and arises as an indispensable run-time platform
for automotive systems. This paper explains the concept of middleware by enumerating its functions and categorizes middleware according to adopted communication models. It also extracts five essential requirements of automotive middleware and proposes a middleware design for automotive systems based on the message-oriented middleware (MOM) structure. The proposed middleware effectively addresses the derived requirements and includes many essential features such as real-time guarantee, fault-tolerance, and a global time base.real-time operating system.
Posted by 봄날병아리
Authors: Jaesoo Lee, Jiyong Park, and Seongsoo Hong
Conference: IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS), pp. 24-33
Status: Published
Date: April, 2006
Full text:
Abstract:
Despite a rapid decrease in the price of solid state memory devices, system memory is still a very precious resource in embedded systems. The use of shared libraries is known to be effective in significantly reducing memory usage. Unfortunately, many resource-constrained embedded systems lack MMU, making it extremely difficult to support this technique.
To address this problem, we propose a novel shared library scheme called the quasi-static shared library. In quasi-static shared libraries, global symbols are bound to pseudo-addresses at linking time and the actual physical addresses are bound at loading time. This scheme is made possible by emulating MMU’s memory mapping feature with a Data Section Base Register (DSBR) and a Data Section Base Table (DSBT). Quasi-static shared libraries do not require symbol tables which take up time and space at runtime.
We have implemented the proposed scheme in a commercial ADSL (Asymmetric Digital Subscriber Line) home network gateway and conducted a series of experiments measuring its memory usage and performance overhead. The result is drastic: a 35%.
reduction in flash memory usage and a 10% reduction
in RAM usage. These results were achieved with only a
negligible performance penalty of less than 4%. Even
though this scheme was applied to uClinux-based
embedded systems, it can be used for any MMU-less
real-time operating system.
Posted by 봄날병아리
Authors: Jaesoo Lee, Jiyong Park, Seunghyun Han, and Seongsoo Hong
Conference: IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA), pp. 117-22
Status: Published
Date: August, 2005
Full text:
Abstract:
The Software Communications Architecture (SCA) is middleware for providing component interfaces and dynamic reconfigurability to software define radio (SDR) modems and it is widely adopted by the SDR forum. Although its main application domains include real-time signal processing, SCA lacks QoS support. We thus propose a QoS-enabled extension of SCA called Q-SCA. Our extended architecture incorporates a new waveform model, extended domain profiles that describe QoS requirements, and a modified application
instantiation process that supports both admission control and resource allocation. We show the viability of Q-SCA through full implementation and experiments.
Posted by 봄날병아리
Authors: Jaesoo Lee, Jiyong Park, Seunghyun Han, and Seongsoo Hong
Conference: The Korea International Robot Week
Status: Published
Date: November, 2004
Full text:
Abstract:
The URC robot project has recently been launched with the aims of popularizing robot systems and putting them to practical use by promoting technical innovations in home service robots. In this paper, we propose a standard software architecture, RSCA, for URC robot applications. RSCA provides a standard operating environment for robot applications together with a framework which expedites the development of such applications. The operating environment of RSCA is comprised of a real-time operating system, distribution middleware, and deployment middleware, which collectively form a hierarchical structure. First, the RTOS is a minimal abstraction layer able to flexibly execute robot applications on an assemblage of diverse hardware devices. The distribution middleware provides an abstraction layer to the applications running in a heterogeneous distributed environment by hiding that heterogeneity and the distribution characteristics from application developers. Finally, the deployment middleware supports reconfiguration of component-based robot applications including such functions as installation, creation, start, stop, tear-down, and un-installation.
Posted by 봄날병아리
Authors: Jiyong Park, and Seongsoo Hong
Conference: Proceedings of 10th International Conference on Real-Time and Embedded Computing Systems and Applications (RTCSA), pp. 41-59
Status: Published
Date: August, 2004
Full text:
Abstract:
There is a growing demand for highly customizable complex software systems, such as real-time operating systems (RTOS), which are composed of existing modules. In an RTOS, crosscutting features frequently occur and they cannot be modularized using the object-oriented and/or component-based software technologies. Aspect-oriented programming (AOP) is a solution for this, because it allows programmers to modularize such crosscutting features via new modules called aspects. However, we have found
that current AOP language implementations have limitations that make them unfit for customizing RTOSes. In this paper, we present enhancements which overcome these limitations. Also, we provide an aspect-oriented programming environment which supports these enhancements. It visualizes the crosscutting relationships of features and enables easy navigation of source code. This is often difficult when using most current AOP languages because the various source files are not easily integrated. We argue that our programming environment enables rapid, highly flexible, and easy customization of complex software systems.
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Authors: Jiyong Park, Saehwa Kim, and Seongsoo Hong
Conference: IEEE Workshop on Object-oriented Real-time Dependable Systems (WORDS). pp. 292-298
Status: Published
Date: October, 2003
Full text:
Abstract:
Despite of the proliferation of object-oriented and component technology, their application to real-time operating systems (RTOS) has been limited since most design concerns in RTOSes crosscut software components and these are critical to deliver required performance and functionality. Aspect-Oriented Programming (AOP) is a very effective means to solve the crosscutting problem. However, we have observed the following limitations of the current AOP framework: (1) the current text-based AOP languages cannot clearly show how aspects are weaved together, (2) their granularity is too coarse to
capture all aspects in an RTOS, (3) it is difficult to control the weaving process, since aspect weavers are usually hard-coded.
In this paper, we propose a new AOP framework that provides (1) a graphical aspect programming environment that visualizes aspects, crosscutting classes, and method structures, (2) a new aspect model that supports a sub-method level granularity where an aspect is defined as a set of classes, and (3) an aspect weaving process specified by an object-oriented meta-model transformation. Since our aspect-oriented programming
framework improves the expressiveness of the crosscutting concerns of RTOSes and automates aspect weaver generation, it can enhance RTOS customization.
Posted by 봄날병아리
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