• International Journal of Control, Automation, and Systems
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• v.1 no.3
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• pp.358-367
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• 2003

We consider discrete-time factorial Markov Decision Processes (MDPs) in multiple decision-makers environment for infinite horizon average reward criterion with a general joint reward structure but a factorial joint state transition structure. We introduce the "localization" concept that a global MDP is localized for each agent such that each agent needs to consider a local MDP defined only with its own state and action spaces. Based on that, we present a gradient-ascent like iterative distributed algorithm that converges to a local optimal solution of the global MDP. The solution is an autonomous joint policy in that each agent's decision is based on only its local state.cal state.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.523-526
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• 1998

In an ongoing project at ETRI-CSTL, A debugger for distributed programs that run on a varied collection of machines is being built. To build such debugger, a clientserver model is incorporated. This strategy enables us to provide a unified user interface and isolate debugger core from the user interface. Several debugging servers running on a diverse set of platforms permit the implementation of a distributed debugger for heterogeneous environment, and the single debugging client provides unified debugging concept and graphical user interface over various servers. Also, the precise specification of the interaction protocol between the client and server facilitates client to be paired with a variety of server implementantations. This paper describes the design and implementation of our debugger, concentrating on the system architecture.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.610-612
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• 2013

A novel balanced distributed amplifier (DA) was proposed using novel impedance transforming MEMS baluns. The impedance transforming MEMS balun is matched to $50{\Omega}$ at one input port and $25{\Omega}$ at two output ports. It is based on the electric field mode-change method, thus it is strongly independent of frequency and very compact. The novel balanced DA consists of two $25{\Omega}$-matched DAs and these are combined by $50{\Omega}$-to-$25{\Omega}$ baluns. Theoretically, it has two times wider bandwidth and power capability than the conventional DA. So as to verify the proposed concept, we designed and fabricated a conventional DA and the proposed one using 0.15-${\mu}m$ GaAs pHEMT technology.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.82.4-82
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• 2001

Requirements for device control networks differ greatly from those of data (business) networks. Consequently, any control network which uses a filedbus protocol is, in general, different from If network protocol TCP/IP. One then needs to integrate both fieldbus protocol and TCP/IP to realize distributed control over IP network or internet. LonWorks technology provides networked intelligent I/O and controllers which make it a powerful, expandable solution. Connecting these remote Lon Works networks to the Internet can provide a powerful, integrated, distributed control system. This paper suggests a basic concept that be applied to distributed control over IP network or internet. Specially, Lonworks technology that used LonTalk protocol is reviewed as device network and ...

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.5
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• pp.227-239
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• 2012

Recent advances in electronics have enabled various conventional products to incorporate with numerous powerful microcontroller. Generally, an embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. The growing performance and reliability of hardware components and the possibilities brought by various design method enabled implementing complex functions that improve the comport of the system's occupant as well as their safety. A cyber physical system (CPS) is a system featuring a tight combination of, and coordination between, the system's computational and physical elements. The concept of cyber physical system, including physical elements, cyber elements, and shared networks, has been introduced due to two general reasons: design flexibility and reliability. This paper presents a cyber physical system where system components are connected to a shared network, and control functions are divided into small tasks that are distributed over a number of embedded controllers with limited computing capacity. In order to demonstrate the effectiveness of cyber physical system, an unmanned forklift with autonomous obstacle avoidance ability is implemented and its performance is experimentally evaluated.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.524-527
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• 2004

New concept of hybrid divisible load theory is introduced in this paper. Hybrid system deals with a combination of modularly divisible load and arbitrarily divisible load. Main idea of hybrid divisible load theory is introduced with a simple example. A condition of optimality is derived for the hybrid case.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.338-341
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• 2004

New concept of hybrid divisible load theory is introduced in this paper. Hybrid system deals with a combination of modularly divisible load and arbitrarily divisible load. Main idea of hybrid divisible load theory is introduced with a simple example. A condition of optimality is derived for the hybrid case.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.4
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• pp.169-177
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• 2009

Concurrent Engineering (CE) has presented new possibilities for successful product development by incorporating various product life-cycle functions from the earlier stage of design. In the product design, geometric representation is vital not only in its traditional role as a means of communicating design information but also in its role as a means of externalizing designer's thought process by visualizing the design product. During the last dozens of years, there has been extraordinary development of computer-aided tools intended to generate, present or communicate 3D models. However, there has not been comparable progress in the development of 3D-CAD systems intended to represent and manipulate a variety of product life-cycle information in a consistent manner. In the previous research, the authors proposed a novel concept called Minus Volume (MV) to incorporate various design information relevant to product life-cycle functions. This paper proposes the use of the MV concept for the collaborative design environment, where many team members are geographically distributed over the networked environment, including Internet, Intranet, WWW, etc. A prototype 3D-CAD system is implemented based on the MV concept and illustrated with the successful implementation of collaborative design example.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2112-2113
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• 2008

The concept is based on distributed wireless sensors that are attached to the incoming and outgoing power lines of secondary substations. A sensor measures only phase current characteristics of the wire it is attached to, is not synchronized to other sensors and does not need configuration of triggering levels. The main novelty of the concept is in detecting and locating faults by combining power distribution network characteristics on system level with low power sampling methods for individual sensors. This concept enables the sensor design to be simple, energy efficient and thus applicable in new installations and for retrofit purposes in both overhead and underground electrical distribution systems.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.835-840
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A vehicle modeling is made of modified Korean High Speed Train bogie model with Vampire program and analyzed the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics. The results would be useful to manage the potential risks in the next stage of basic and precision design that will be done by the manufacturing company.