• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.364-364
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• 2000

Timed Petri Net(TPN) is one of methods to model and to analyze Discrete Event Dynamic Systems(DEDSs) with real time values. It has two time values, earliest firing time ($\alpha$$_{i}$) and latest firing time ($\beta$$_{I}$) for the each transition. A transition of TPN is fired at arbitrary time of time interval ($\alpha$$_{I}$, $\beta$$_{i}$). Uncertainty of firing time gives difficulty to analyze and estimate a modeled system. In this paper, we proposed the Fuzzy Transition Timed Petri Net(FTTPN) with fuzzy theory to determine the optimal transition time (${\gamma}$$_{i}$). The transition firing time (${\gamma}$$_{i}$) of FTTPN is determined from fuzzy controller which is modeled with information of state transition. Each of the traffic signal controllers are modeled using the proposed method and timed petri net. And its Performance is evaluated by simulation of traffic signal controller. controller.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.187-193
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• 2005

In this paper, we proposes a man-machine interface design for fault diagnosis system with inter-node search method in a Petri net model. First, complicated fault cases are modeled as the Petri net graph expressions. Next, to find out causes of the faults on which we focus, a Petri net model is analyzed using the backward reasoning of transition-invariance in the Petri net. In this step, the inter-node search method algorithm is applied to the Petri net model for reducing the range of sources in faults. Finally, the proposed method is applied to a fault diagnosis of a refrigeration system to confirm the validity of the proposed method.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.391-393
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• 2002

DSTM 기술은 IPv6 네트워크가 도입되기 시작함에 따라 논의되어야 할 가장 중요한 이슈들 중 하나로서 기존의 IPv4 에서 IPv6 로의 자연스러운 이전을 지원해 주는 IPv6 트랜지션 기술 중 하나이다. 이 기술은 IPv6 망에서 dual stack 을 기본으로 채택하여 해당IPv6 호스트의 IPv4 응용을 수정하지 않고 IPv6 터널링(Tunneling) 기술을 채택하여 목적지 IPv4 응용과의 통신을 제공한다. 본 논문은 이러한 DSTM 요소 기술 중 하나인 IPv6 호스트에 동적으로 IPv4 주소를 할당, 해제 및 IPv6 터널링을 관리 하는 DSTM Server와Client의 설계 및 구현을 기술한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.620-628
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• 1997

When the Chebyshev function is applied to design the waveguide transition, it exhibits poor impedance matching characteristics due to impedance discontinuities at the ends of tapered line. In this paper, an improved Chebyshev function, which is obtained by using the convolution property, is proposed to make improvements on the impedance matching characteristics of the waveguide transition. When rectangular to circular waveguide transition is designed by improved function, then the computed return loss is approximately 5 dB better than the conventional Chebyshev function.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.32-37
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• 2001

This paper describes a noble fault diagnosis method using inter node search technique in PN model. First, a complicated fault system is modeled as PN graphic expressions. Next, to find out sources for faults on which we focus, the PN model is analyzed using the backward chaining of T-invariance. In this step, the technique of inter node search is applied for reducing some range of sources in a fault. Also, colnposing method of incidence matrix in PN is proposed. Then, it makes the diagnosis system to very flelible system because new knowledges about the sources in a fault can be added easily to conventional systems. Finally, the proposed method is applied to the automobile trouble diagnosis system to confirm the validity of the method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.264-267
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• 2000

The need for including time variables in various type of modeled Discrete Event Dynamic Systems(DEDSs) is apparent since the modeled systems are real time in nature. In the real world, almost all event is related to time. A Time Petri Net(TPN) is one of methods for model ins and analyzing of DEDSs with real time values. Two time values, ${\alpha}$$\sub$i/ and ${\beta}$$\sub$i/ are defined for each transition. In this paper, Ire present Fuzzy Transition Timed Petri Net(FTTPN) to determine the optimal transition firing time between ${\alpha}$$\sub$i/ and ${\beta}$$\sub$i/ using fuzzy theory. The traffic signal controller in an intersection is modeled and analyzed by FTTPN.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2321-2323
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• 2005

본 논문에서는 지수형으로 테이퍼 된 슬롯 안테나로 광대역 안테나를 설계하였다. 이 안테나는 VSWR${\leq}2$를 기준으로 $6GHz{\sim}18GHz$까지 3:1의 광대역 특성을 나타낸다. 급전부는 마이크로스트립으로 설계되었고 안테나는 싱글 슬롯으로 설계하였기 때문에 급전부와 안테나 사이의 트랜지션은 marchand balun을 이용하여 해결하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.5
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• pp.40-45
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• 2008

In this paper, a microstrip linear tapered slot antenna is designed. A tapered slot antenna(TSA) has many advantages such as low profile, low weight, easy fabrication, and compatibility with monolithic microwave integrated circuits(MMIC). In addition, it has demonstrated multi octave bandwidth, moderately high gain, and symmetrical E- and H-plane beam patterns. A feed network is implemented with transition between a microstrip and a slot line for the microstrip linear tapered slot antenna. The transition is consist of two sides. One side has a microstrip line, the other side has a slot line. The dimensions of the microstrip and slot line are ${\lambda}_m/4$ and ${\lambda}_s/4$ at the center of the cross section of the microstrip and slot line. In order to get broad bandwidth antenna characteristics, the tapered length is chosen as $4{\lambda}_o$ and termination width is chosen as $1.75{\lambda}_o$. Experimental results show that the microstrip tapered slot antenna has symmetrical E- and H-plane beam patterns with around 5GHz of bandwidth at center frequency of 5.0GHz.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1503-1514
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• 2006

Today, consumers can access Internet from everywhere, therefore most commercial and other organizations provide their services on the Web. As the result, countless Web service systems are already on the Internet and more systems are under construction. Therefore, many researches of verifying that the system to be constructed will not have any deadlock and will run successfully without any problem at the early stage of design have been performed. Several Petri net based verification methods have also been published. However, they have focused on building Petri net models of Web service systems and none of them introduces efficient analysis methods. As a mathematical technique with which we can find the minimum duration time needed to fire all the transitions at least once and coming back to the initial marking in a timed net, the minimum cycle time method has been widely used in computer system analysis. A timed net is a modified version of a Petri net where a transition is associated with a delay time. A delay time used in a timed net is a constant even though the duration time associated with an event in the real world is a stochastic number in general. Therefore, this paper proposes 'Mixedly Distributed Stochastic Timed Net' where a transition can be associated with a stochastic number and introduce a minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net'. We also introduce a method of analysing a Web service system's response time with the minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net.'.

• Journal of Korea Multimedia Society
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• v.1 no.2
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• pp.224-238
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• 1998

The EMFG (Extended Mark Flow Graph) is not only a powerful tool for designing the discrete-event system conceptually or specifically but also a good representation tool for implementing the system directly. But it is difficult to design or analyze the system because the impossibility of mathematical analysis results from some complicated representation of the EMFG. In this paper, therefore we redefined EMFG representations to provide the possibility of mathematical analysis, and employed an output inhibit are of a transition, which makes possible the adequate representations for the indescribable parts. We also solved trouble parts in the circuit translations of the EMFG and proposed the circuit translation method by using the mathematical formula. Finally, we compared the conventional EMFG with the redefined EMFG, and we designed a 0101 detecter with the redefined EMFG and translated it to the corresponding circuit.