• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권3호
• /
• pp.465-472
• /
• 2017

Security has become one of the most important requirements for various devices for multi-sensor based embedded systems. The AES (Advanced Encryption Standard) algorithm is widely used for security, however, it requires high computing power. In order to reduce the CPU power for the data encryption of images, we propose a new image encryption module using hardware memoization, which can reuse previously generated data. However, as image pixel data are slightly different each other, the reuse rate of the simple memoization system is low. Therefore, we further apply an approximate concept to the memoization system to have a higher reuse rate by sacrificing quality. With the novel technique, the throughput can be highly improved by 23.98% with 14.88% energy savings with image quality loss minimization.

• Journal of Computing Science and Engineering
• /
• 제11권2호
• /
• pp.58-68
• /
• 2017

While graphics processing units (GPUs) can be used to improve the performance of real-time embedded applications that require high throughput, it is challenging to estimate the worst-case execution time (WCET) of GPU programs, because modern GPUs are designed for improving the average-case performance rather than time predictability. In this paper, a reordering framework is proposed to regulate the access to the GPU data cache, which helps to improve the accuracy of the estimation of GPU L1 data cache miss rate with low performance overhead. Also, with the improved cache miss rate estimation, tighter WCET estimations can be achieved for GPU programs.

• 인터넷정보학회논문지
• /
• 제17권5호
• /
• pp.121-129
• /
• 2016

Company A, an embedded system manufacturer, has been managing multiple development projects. Executives need to understand the risk level of every project and prioritize resource distribution. Traditional project monitoring tools or excel sheets are too complex for calculating the risk factors across a functional organization. Two new charts, "Spear-head Chart" and "Float Chart" were designed to assist high level decision making processes. Two charts were used for weekly executive meetings in order to monitor project progress and rectify project direction. One page graphical monitoring tools in Company A are good enough for high management decision making. Authors explain the characteristics of two charts and propose its practical implementation in real working environment. Spear-head chart was also implemented as a system.

• International Journal of Concrete Structures and Materials
• /
• 제10권2호
• /
• pp.143-147
• /
• 2016

In recent years, some modifications were introduced in the stress-strain relationship of the steel in order to develop a more efficient shear model for reinforced concrete members. The last contribution in this sense corresponding to the Refined Compression Field Theory (RCFT, 2009); this theory proposed a steel constitutive model that has account the tension stiffening area prescribed by technical codes, what simplifies all the design process. However, under certain design conditions supported by such codes, the RCFT model does not provide a real (non-complex) solution for the steel yield strain when the prescribed tension stiffening area is considered; then the load-strain response cannot be computed. In this technical note, the tension stiffening area is fixed in order to guarantee the application of the embedded steel constitutive model for all the standard design range.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (A)
• /
• pp.130-132
• /
• 2004

프로세서, 센서 등의 소형화와 저가격화는 어느 곳에서나 유무선 네트웍과 연결되는 편재형 디바이스들의 출연을 가능하게 했다. 이러한 디바이스들은 점점 많은 기능을 가지고 인텔리전트한 기능을 제공하고 있다. 그러나 기존의 상용 RTOS는 특정 제품에의 의존도가 높고, 멀티미디어 응용과 같은 새로운 편재환경에의 요구 사항을 지원하고 있지 않으므로 이러한 환경변화에 적응하는 것이 어렵다. 따라서 소형의 휴대 정보 단말에서부터 홈 서버에 이르기까지 다양한 종류의 편재형 기기에 사용될 수 있는 확장성과 풍부한 기능을 갖춘 표준 실시간 OS의 개발이 필요하다. Qplus-P는 이와 같은 편재형 컴퓨팅을 지원하기 위한 실시간 소프트웨어 플랫폼이다. 이에는 실시간 운영체제 커널, 라이브러리 및 응용, 사용자 개발 도구가 포함된다. 특히 커널은 확장 가능한 구조를 채택하여 다양한 내장형 기기에 적용 가능한 이식성을 지원하며, 사용자 개발 도구는 특정 내장형 기기에서의 OS의 이식을 지원하는 개발 도구로 편리한 사용자 인터페이스를 제공한다.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2009년도 추계학술발표논문집
• /
• pp.461-465
• /
• 2009

Normally, a distributed computing environment is flexible in controlling complex embedded systems but their software components are becoming complex as these systems are equipped with several platforms and attached to various electronic devices, sensors, and actuators. These systems requires inter-object communication mechanisms to provide fault tolerant and QoS-enabled middleware service support in a distributed system. Generally, a middleware performs analysis of the parameters to ensure the availability and reliability of data dissemination. This paper focuses in particular to designing an application middleware for the specific scenario to improve the high availability and fault tolerance of data thus improving the QoS (Quality of Service) of a distributed system. The performance of an adaptive and highly reliable middleware can be significant based on the selection of vital parameters of the system.

• Journal of Computing Science and Engineering
• /
• 제6권4호
• /
• pp.257-266
• /
• 2012

This paper overviews clock design problems related to the circuit reliability in deep submicron design technology. The topics include the clock polarity assignment problem for reducing peak power/ground noise, clock mesh network design problem for tolerating clock delay variation, electromagnetic interference aware clock optimization problem, adjustable delay buffer allocation and assignment problem to support multiple voltage mode designs, and the state encoding problem for reducing peak current in sequential elements. The last topic belongs to finite state machine (FSM) design and is not directly related to the clock design, but it can be viewed that reducing noise at the sequential elements driven by clock signal is contained in the spectrum of reliable circuit design from the clock source down to sequential elements.

• Interaction and multiscale mechanics
• /
• 제4권3호
• /
• pp.219-237
• /
• 2011

Recent advances in scientific computing enable the full atomistic simulation of DNA molecules. However, there exists length and time scale limitations in molecular dynamics (MD) simulation for large DNA molecules. In this work, a two-level homogenization of DNA molecules is proposed. A wavelet projection method is first introduced to form a coarse-grained DNA molecule represented with superatoms. The coarsened MD model offers a simplified molecular structure for the continuum description of DNA molecules. The coarsened DNA molecular structure is then homogenized into a three-dimensional beam with embedded molecular properties. The methods to determine the elasticity constants in the continuum model are also presented. The proposed continuum model is adopted for the study of mechanical behavior of DNA loop.

• 전자통신동향분석
• /
• 제31권4호
• /
• pp.55-64
• /
• 2016

컴퓨터 시스템을 위한 소프트웨어 개발에 있어 성능 최적화는 하드웨어 및 운영체제에 대한 전문 지식과 다양한 상황을 고려할 수 있는 숙련을 필요로 하는 매우 어려운 작업으로 알려져 있다. 특히, 임베디드 시스템의 경우 사용되는 하드웨어와 운영체제의 종류가 매우 다양하여 임베디드 소프트웨어의 성능 최적화에는 더욱 많은 시간과 노력이 요구된다. 자가적응형 컴퓨팅은 소프트웨어 개발에 있어 성능 최적화 작업 노력을 최소화하기 위한 기술로 소프트웨어 실행을 실시간으로 감시하면서 소프트웨어 실행에 관여하는 다양한 컴퓨터 시스템 리소스들을 제어하여 소프트웨어가 요구하는 성능을 자동으로 맞춰주는 컴퓨팅 기술이다. 본고에서는 자가적응형 컴퓨팅 기술 현황을 살펴본 후 임베디드 디바이스를 위한 자가적응형 컴퓨팅 기술 개발 사례를 소개한다.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권1호
• /
• pp.79-85
• /
• 2017

In this paper, several optimizations are proposed to enhance the quality of lane detection algorithms in automotive applications. Considering the diagonal directions of lanes, the proposed limited Hough transform newly introduces image-splitting and angle-limiting schemes that relax the number of possible angles at the line voting process. In addition, unnecessary edges along the horizontal and vertical directions are pre-defined and removed during the edge detection procedures, increasing the detecting accuracy remarkably. Simulation results shows that the proposed lane recognition algorithm achieves an accuracy of more than 90% and a computing speed of 92 frame/sec, which are superior to the results from the previous algorithms.