• 한국정보통신학회논문지
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• 제6권2호
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• pp.159-168
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• 2002

실시간 객체지향 분산 컴퓨팅은 객체 네트워크 형태에서 분산된 컴퓨터 시스템 구조와 관련 된 실시간 분산 컴퓨팅의 한가지 형태이다. 최근에 실시간 응용분야에 적합한 기존의 객체지향 시스템 구조를 확장한 몇 가지 의 구조가 제안되었다. 실시간 시뮬레이션 프로그램의 하나인 시간 및 메시지 트리거 객체지향 프로그램밍이 분산된 시간 트리거 시뮬레이션으로 설계될 수 있으며, 일반적이고 보편적인 설계 타입으로서 사용되고, 하나 의 실시간 시뮬레이션 패러다임으로 제안하였다. 실시간 객체지향 프로그램밍은 안전을 중요시하게 여기는 응용분야에 적용할 수 있으며, 실시간 운영체제 시스템 커널로서 객체지향 프로그램밍 언어인 비쥬얼 C++언어로 작성되었다. 응용 시스템에서 실시간 서비스를 보장하기 위한 설계자들의 노력을 현저하게 줄일 수 있는 장점을 가지고 있다.

• Journal of Computing Science and Engineering
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• 제1권1호
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• pp.56-73
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• 2007

Demands have been growing in safety-critical application fields for producing networked real-time embedded computing (NREC) systems together with acceptable assurances of tight service time bounds (STBs). Here a service time can be defined as the amount of time that the NREC system could take in accepting a request, executing an appropriate service method, and returning a valid result. Enabling systematic composition of large-scale NREC systems with STB certifications has been recognized as a highly desirable goal by the research community for many years. An appealing approach for pursuing such a goal is to establish a hard-real-time (HRT) component model that contains its own STB as an integral part. The TMO (Time-Triggered Message-Triggered Object) programming scheme is one HRT distributed computing (DC) component model established by the first co-author and his collaborators over the past 15 years. The TMO programming scheme has been intended to be an advanced high-level RT DC programming scheme that enables development of NREC systems and validation of tight STBs of such systems with efforts far smaller than those required when any existing lower-level RT DC programming scheme is used. An additional goal is to enable maximum exploitation of concurrency without damaging any major structuring and execution approaches adopted for meeting the first two goals. A number of previously untried program structuring approaches and execution rules were adopted from the early development stage of the TMO scheme. This paper presents new concrete justifications for those approaches and rules, and also discusses new extensions of the TMO scheme intended to enable further exploitation of concurrency in NREC system design and programming.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.421-426
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• 2004

Analyzing adaptive possibilities of agents in multi-agents system, we have discovered new aspects of ambient intelligence in distributed modular systems using intelligent building blocks (I-BLOCKS) [1]. This paper describes early scientific researches related to technical design, applicable experiments and evaluation of adaptive processing and information interaction among I-BLOCKS allowing users to easily develop ambient intelligence applications. The processing technology presented in this paper is embedded inside each DUPLO1 brick by microprocessor as well as selected sensors and actuators in addition. Behaviors of an I-BLOCKS modular structure are defined by the internal processing functionality of each I-Blocks in such structure and communication capacities between I-BLOCKS. Users of the I-BLOCKS system can do 'programming by building' and thereby create specific functionalities of a modular structure of intelligent artefacts without the need to learn and use traditional programming language. From investigating different effects of modem artificial intelligence, I-BLOCKS we have developed might possibly contain potential possibilities for developing applications in ambient intelligence (AmI) environments. To illustrate these possibilities, the paper presents a range of different experimental scenarios in which I-BLOCKS have been used to set-up reconfigurable modular systems. The paper also reports briefly about earlier experiments of I-BLOCKS in different research fields, allowing users to construct AmI applications by a just defined concept of modular artefacts [3].

• Advances in Computational Design
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• 제5권3호
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• pp.233-260
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• 2020

The main purpose to introduce model based controller in proposed control technique is to provide better and fast learning of the floating dynamics by means of fuzzy logic controller and also cancelling effect of nonlinear terms of the system. An iterative adaptive dynamic programming algorithm is proposed to deal with the optimal trajectory-tracking control problems for autonomous underwater vehicle (AUV). The optimal tracking control problem is converted into an optimal regulation problem by system transformation. Then the optimal regulation problem is solved by the policy iteration adaptive dynamic programming algorithm. Finally, simulation example is given to show the performance of the iterative adaptive dynamic programming algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.36.6-36
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• 2001

The problem of robot navigation and control is a complex task. Its complexity and characteristics depends on the characteristics of the environment robot inhabits, robot construction (mechanical abilities to move, sense) and the job the robot is supposed to do. In this paper we propose a hybrid programming approach to mobile robot navigation and control in an indoor environment. In our approach we used declarative, procedural, and object oriented programming paradigms and we utilized some advantages of our distributed computing architecture. The programming languages corresponding to the paradigms we used were C, C++ and Prolog. In the paper we present some details of our mobile robot hardware and software structure, focusing on the software design and implementation.

• Journal of Information Processing Systems
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• 제18권1호
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• pp.159-172
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• 2022

The role of the interconnect network, which connects computing nodes to each other, is important in high-performance computing (HPC) systems. In recent years, the peripheral component interconnect express (PCIe) has become a promising interface as an interconnection network for high-performance and cost-effective HPC systems having the features of non-transparent bridge (NTB) technologies. OpenSHMEM is a programming model for distributed shared memory that supports a partitioned global address space (PGAS). Currently, little work has been done to develop the OpenSHMEM library for PCIe-interconnected HPC systems. This paper introduces a prototype implementation of the OpenSHMEM library through a switchless interconnect network using PCIe NTB to provide a PGAS programming model. In particular, multi-interrupt, multi-thread-based data transfer over the OpenSHMEM shared memory model is applied at the implementation level to reduce the latency and increase the throughput of the switchless ring network system. The implemented OpenSHMEM programming model over the PCIe NTB switchless interconnection network provides a feasible, cost-effective HPC system with a PGAS programming model.

• 정보기술과데이타베이스저널
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• 제7권2호
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• pp.33-45
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• 2000

Uniview system is a client-server system that runs on heterogeneous distributed systems and supports the debugging of various kinds of programs. Its client system provides a unified debugging concept and interface on various debuggers of heterogeneous hosts. Its server system provides debugging services and features openness and scalability by interoperating with one or more debugger processes existing on the same host. Based on FSF(Free Software Foundation)'s gdb and Sun Microsystems's dbx. Uniview system supports C/C++ programming language in various UNIX environments as well as Windows environments. The proposed system was designed and implemented to support the JAVA language, which is prevalently used in recent heterogeneous distributed systems and was partly extended to make a clear analysis of JAVA class file structure. Sun Microsystems's Jdb supplied as a JAVA debugger has very limited functions compared to other programming language debugger. In this paper, Uniview as a JAVA debugging system was implemented to provide debugging technologies which are necessary to debug Java applications but missing in current JAVA language as well as to provide its users with various information.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.573-579
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• 2011

To meet the scalability and performance requirements of data analyses, which often involve voluminous data, efficient parallel or concurrent algorithms and frameworks are essential. We present a high-performance Korean morphological analyzer which employs the MapReduce framework on the graphics processing unit (GPU). MapReduce is a programming framework introduced by Google to aid the development of web search applications on a large number of central processing units (CPUs). GPUs are designed as a special-purpose co-processor. Their programming interfaces are typically formulated for graphics applications. Compared to CPUs, GPUs have greater computation power and memory bandwidth; however, GPUs are more difficult to program because of the design of their architectures. The performance of the Korean morphological analyzer using the MapReduce framework on the GPU is evaluated in comparison with the CPU-based model. The proposed Korean Morphological analyzer shows promising scalable performance on distributed computing with the GPU.

• Journal of Power Electronics
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• 제9권6호
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• pp.919-928
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• 2009

Microgrids (MGs) are typically comprised of distributed generators (DGs) including renewable energy sources (RESs), storage devices and controllable loads, which can operate in either interconnected or isolated mode from the main distribution grid. This paper introduces a novel dynamic programming (DP) approach to MG optimization which takes into consideration the coordination of energy supply in terms of heat and electricity. The DP method has been applied successfully to several cases in power system operations. In this paper, a special emphasis is placed on the uncontrollability of RESs, the constraints of DGs, and the application of demand response (DR) programs such as directed load control (DLC), interruptible/curtaillable (I/C) service, and/or demand-side bidding (DSB) in the deregulated market. Finally, in order to illustrate the optimization results, this approach is applied to a couple of examples of MGs in a certain configuration. The results also show the maximum profit that can be achieved.

• 한국경영과학회지
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• 제39권4호
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• pp.19-31
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• 2014

We study parallel processing techniques for the R programming language of high performance computing technology. In this study, we used massively parallel computing system which has 25,408 cpu cores. We conducted a performance evaluation of a distributed memory system using MPI and of a the shared memory system using OpenMP. Our findings are summarized as follows. First, For some particular algorithms, parallel processing is about 150 times faster than serial processing in R. Second, the distributed memory system gets faster as the number of nodes increases while shared memory system is limited in the improvement of performance, due to the limit of the number of cpus in a single system.