• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.676-680
• /
• 1994

Three synchronic variables (Deviation Time, Fairness Time, Synchronic Time) are defined for Timed Place Petri Nets (TPPN). These parameters show the dependency between the firing of transition subsets in the time domain by different values. The approaches in this paper can be used to find synchronic relations in Stochastic Petri Nets. This paper presents how to decide the minimum resources required to a Flexible Manufacturing Cell using Synchronic Time concept.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.10 no.5
• /
• pp.513-519
• /
• 2000

In this paper, we investigate some properties of fuzzy r-cluster points and fuzzy r-limit points in smooth fuzzy topological spaces. We define fuzzy r-convergent nets and investigate some of their properties.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.488-492
• /
• 1991

This paper deals with modeling and scheduling for flexible manufacturing systems(FMS). In modeling extended Petri nets are used to describe various and complex properties. To resolve multiple conflict without predefined properties, such as part selection, machine selection, rule-based scheduling method is introduced. This structure have a capability of on-line scheduling with systematic modeling description.

• Proceedings of the Korea Contents Association Conference
• /
• 2010.05a
• /
• pp.390-392
• /
• 2010

Mobile grid system supports the integration mobile devices as grid resources. Availability of mobile resources changes dynamically in mobile grid system. Stochastic reward nets (SRN) is an extension of stochastic Petri nets and provides compact modeling facilities for system analysis. We build the SRN model to represent availability of mobile resources with disconnected operation service.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.4
• /
• pp.255-267
• /
• 2004

This study was conducted in order to improvement of fishing gear and fishing operating system for anchovy boat seine by bag net A-type and B-type was attached with half size modified nets. Field experiments were carried out observe geometry of nets by catcher boats. The obtained results are summarized as follows : The actual ratio of net opening in each part of the half size modified nets was increased from fore part to back part of the nets as shown the smallest value about 20% in wing net and the biggest value about 110% in bag net. In addition, vertical net opening of B-type net as measured as 10.9~11.8m in fore bag net and 5.8~8.0m in after bag net were 1~2m greater than 9.0~13.6m of A-type one, and 2~3m less than 9.3~10.4m of A-type one, respectively. Vertical net opening of half size modified net was shown as less variation of towing depth from wing net to inside wing net than those of traditional nets due to stable vertical performance. The mesh distortion or drift and variation of vertical net opening were decreased by improvement of bag nets in order to minimized shape of net pocket phenomenon whenever towing speed is slow. Bag net B-Type attached with dual flapper was shown as less variation in width of bag net and less escapement of anchovy.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.1
• /
• pp.36-44
• /
• 2008

This paper proposes a modeling and simulation process of a panel production line (PPL) in a shipyard. The panel production line is an assembly process to produce a main panel of a flat block and a curved block. In this paper, its activity analysis is carried out using expression of IDEF0, and its process is qualitatively and quantitatively analyzed and modeled by Petri Nets. A commercial discrete event simulation tool, $QUEST^{TM}$, is used for virtual PPL and simulation. The modeling results by Petri Net are mapped to elements of the simulation tool. Finally, an integrated simulation environment of PPL is implemented in order to efficiently utilize the virtual PPL model. With the help of IDEF0 and Petri Nets, we could systematically analyze and describe the PPL process that are characterized as being concurrent, asynchronous, distributed, parallel, nondeterministic, and/or stochastic. Also, the dynamic and concurrent activities of a PPL system were able to be simulated. A timing concept can be included into the Petri nets model to evaluate performance and dependability issues of the system.

• The KIPS Transactions:PartC
• /
• v.8C no.5
• /
• pp.621-628
• /
• 2001

SET is one of the useful protocol for credit payment in the Electronic market. Since, the delivery problem is conformed to delivery cooperation not payment problem, the classic SET protocol didn\`t consider about the certification of delivery. But the environment of electronic market be changed to manage the sold, delivery and payment etc.. In this paper, based on this consider, we propose a new SET protocol which has an function to verify the delivery based on SKP and verify it after analyzed by Petri nets. Specially, we consider SKP between Customer, Merchant, and Acquirer for improve the verify function.

• Journal of Internet Computing and Services
• /
• v.5 no.4
• /
• pp.115-124
• /
• 2004

This paper presents a weighted fuzzy backward reasoning algorithm for rule-based systems based on weighted fuzzy Petri nets. The fuzzy production rules in the knowledge base of a rule-based system are modeled by weighted fuzzy Petri nets, where the truth values of the propositions appearing in the fuzzy production rules and the certainty factors of the rules are represented by fuzzy numbers. Furthermore, the weights of the propositions appearing in the rules are also represented by fuzzy numbers. The proposed weighted fuzzy backward reasoning generates the backward reasoning path from the goal node to the initial nodes and then evaluates the certainty factor of the goal node. The algorithm we proposed can allow the rule-based systems to perform weighted fuzzy backward reasoning in more flexible and human-like manner.

• The Journal of the Korea Contents Association
• /
• v.8 no.1
• /
• pp.300-307
• /
• 2008

Power management (PM) depends on the power state transition and system workload. The system model is composed of corresponding stochastic models of the power state and system queue. In this paper, stochastic models which can handle various PM techniques are developed. SRN (Stochastic Reward Nets), an extended Petri-Net, has facilities that represent system queue and various modelling functions. The SRN is employed for developing PM models. An adaptive timeout PM model is also introduced and the power consumption and performance of this model are compared with other existing PM techniques models such as greedy and N-Policy techniques.

• The Journal of the Korea Contents Association
• /
• v.8 no.1
• /
• pp.169-176
• /
• 2008

In this paper, we develop radio resource management queueing model in IEEE 802.IS networks considering both connection and packet level. In the upper level connection, we model connection admission control depending on availability of bandwidth and priority queue in each service class. In the lower level packet, we model dynamic bandwidth allocation considering threshold and availability of bandwidth in each service class simultaneously. Hierarchical model is built using an extended Petri Nets, SRN (Stochastic Reward Nets). Bandwidth utilization and normal throughput as performance index for all service classes of traffic are calculated and numerical results are obtained.