• Journal of Advanced Navigation Technology
• /
• v.16 no.1
• /
• pp.145-150
• /
• 2012

This paper explains a performance analysis of an error detection system running on nested session management of cloud computing collaboration environment using rule-based DEVS modeling and simulation techniques. In DEVS, a system has a time base, inputs, states, outputs, and functions. This paper explains the design and implementation of the FDA(Fault Detection Agent). FDA is a system that is suitable for detecting software error for multimedia remote control based on nested session management of cloud computing collaboration environment.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.2
• /
• pp.454-460
• /
• 2000

In this paper, an architecture is suggested which efficiently detects intrusions in network environments. In the architecture, the Blackboardbased agent coordinates opinions of several independent agents which are performing unique functions, by resolving conflicts and reconfirming notices of intrusion. In the simulation, it was found that conventional agents judge simple resource access activities as 'intrusion' while blakcboard-based agent reserves the judgement until additional information confirms notices of independent agents. Reconfirmation process based on additional questioning will roduce positive errors.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2019.05a
• /
• pp.548-551
• /
• 2019

강화 학습은 일반적으로 제어 로봇과 관련이 있는 순차적 의사결정을 위한 학습의 한 형태이다. 이 강화 학습은 행동에 대한 보상을 최대로 하는 정책을 학습하는 것을 목표로 한다. 하지만, 강화 학습을 실제 세계에 적용하기에는 많은 제약사항이 존재하며 실제 세계의 복잡한 환경에서 좋은 정책을 학습하는 것은 매우 어렵다. Unity는 강화 학습 시뮬레이션을 위한 전용 Toolkit을 제공한다. 이러한 이유로 Unity를 시뮬레이터로서 사용하는 것이 좋은 정책을 학습하는 훈련의 근거가 된다. 따라서 본 논문에서는 강화 학습을 실제 세계에 바로 적용시키기 전에 Unity Machine Learning Agents Toolkit을 사용하여 실제 세계와 비슷한 환경을 만들고 강화 학습을 통해 에이전트를 미리 학습시켜보는 과정을 수행해봄으로써 시뮬레이터의 필요성을 부각시킨다.

• KIPS Transactions on Software and Data Engineering
• /
• v.11 no.8
• /
• pp.331-338
• /
• 2022

Successor representation (SR) is a model of human reinforcement learning (RL) mimicking the underlying mechanism of hippocampal cells constructing cognitive maps. SR utilizes these learned features to adaptively respond to the frequent reward changes. In this paper, we evaluated the performance of SR under the context where changes in latent variables of environments trigger the reward structure changes. For a benchmark test, we adopted SR-Dyna, an integration of SR into goal-driven Dyna RL algorithm in the 2-stage Markov Decision Task (MDT) in which we can intentionally manipulate the latent variables - state transition uncertainty and goal-condition. To precisely investigate the characteristics of SR, we conducted the experiments while controlling each latent variable that affects the changes in reward structure. Evaluation results showed that SR-Dyna could learn to respond to the reward changes in relation to the changes in latent variables, but could not learn rapidly in that situation. This brings about the necessity to build more robust RL models that can rapidly learn to respond to the frequent changes in the environment in which latent variables and reward structure change at the same time.

• Korean Management Science Review
• /
• v.29 no.1
• /
• pp.153-168
• /
• 2012

Order allocation is one of the most important decision-making problems of firms having significant influences on performances of themselves and the whole supply chain. Existing researches about order allocation have mainly focused on evaluating capabilities of directly connected suppliers so that it is hard to consider effects and interactions from undirected connections over multiple lower-layers. To alleviate the limitation, this paper proposed a novel approach to order allocation using structural hole. By applying the concept of structural hole to the supply network, we could evaluate the structural supplying powers of firms with respect to both of direct and indirect connections. In the proposed approach, we derived a methodology to measure the potential supplying power of each firm by modifying the effective size as one of the measurements of structural hole and then, proposed its application, the structural hole based order allocation strategy. Furthermore, we conducted the agent based modeling of supply chain to perform the decision-making process of order allocation and simulated the proposed strategy. As a results, by coping with the variance of demand more stably, it could improve the performance of supply chain from the aspects of fill rate, inventory level and demand-supply balance.

• The KIPS Transactions:PartC
• /
• v.11C no.7 s.96
• /
• pp.895-904
• /
• 2004

Due to the frequent and unpredictable topology changes, multicast still remains as challenge and no one-size-fits-all protocol could serve all kinds of needs in mobile ad hoc network. In this paper, we propose a novel scheme of Hierarchical Eulerian Ring Oriented Multicast Architecture (HEROMA) over mobile ad hoc network. It has features that concentrate on efficiency and robustness simultaneously. It is also an application-driven proposal for hazard detection. Architectures including Eulerian ring, hierarchy and multicast agent are investigated in detail Simulation results different level of improvements on control traffic, end-to-end delay and packet delivery ratio by comparing with tree-based and mesh-based multicast protocols.

• The Journal of the Korea Contents Association
• /
• v.6 no.11
• /
• pp.285-294
• /
• 2006

In this paper, we propose a new remote control and monitoring technique using web-service technology for URC robot. URC robot needs the architecture which can be applied all over the variety hardware and software platform for supporting the several interface with external world in the ubiquitous environment. In this paper, web-service technology is preferentially deliberated how to adopt into the embedded environment and the remote control and monitoring technology based on web-service technology for URC robot is designed and implemented as to support the interaction with agent programs. It has been carried out through simulating and implementing this technology into the target robot called NETTORO and proved its practical worth.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.4 no.1
• /
• pp.14-19
• /
• 2009

In Mobile Ad-hoc Network, link failure and packet loss may occur frequently due to its nature of mobility and limited battery life. In this paper, an enhanced robust routing protocol based on AODV(Ad hoc On-demand Distance Vector routing) by monitoring variation of receiving signal strength is proposed. New metric function that consists of node mobility and hops of path is used for routing decision. For preventing route failure by node movement during data transmission, a new route maintenance is presented. If the node movement is detected, the routing agent switches local path to its neighbor node. Simulation results show that the performance of the proposed routing scheme is superior to previous AODV protocol.

• Journal of the Korea Society for Simulation
• /
• v.24 no.4
• /
• pp.107-118
• /
• 2015

Many approaches to agent collaboration have been introduced in military war-games, and those approaches address methods for simulation entity (actor) collaboration within a team to achieve given goals. To meet fast-changing battlefield situations, an actor must be loosely coupled with their tasks and be able to take over the role of other actors if necessary to reflect role handovers occurring in real combat. Achieving these requirements allows the transfer of tasks assigned one actor to another actor in circumstances when that actor cannot execute its assigned role, such as when destroyed in action. Tight coupling between an actor and its tasks can prevent role handover in fast-changing situations. Unfortunately, existing approaches and war-game strictly assign tasks to actors during design, therefore they prevent the loose coupling. To overcome these shortcomings, our Role-based Command Hierarchy (ROCH) model dynamically assigns roles to actors based on their situation at runtime. In the model, "Role" separates actors from their tasks. In this paper, we implement the ROCH model as a component that uses a publish-subscribe pattern to handle the link between an actor and the roles of its subordinates (other actors).

• Journal of the Korea Computer Industry Society
• /
• v.3 no.2
• /
• pp.209-216
• /
• 2002

World Wide Web has potential possibility of infrastructure for parallel computing environment connecting massive computing resources, not just platform to provide and share information via browser. The approach of Web-based parallel computing has many advantages of the ease of accessibility, scalability, cost-effectiveness, and utilization of existing networks. Applet has the possibility of decomposing the independent/parallel task, moving over network, and executing in computers connected in Web, but it lacks in the flexibility due to strict security semantic model. Therefore, in this paper, Web-based parallel computing environment using mobile agent, Aglet (Agile applet) was designed and possible implementation technologies and architecture were analyzed. And simple simulation and analysis was done compared with applet-based approach.