• The KIPS Transactions:PartA
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• v.14A no.6
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• pp.333-340
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• 2007

In multi agent systems, various inter agent communication models have been proposed, and, especially, there are several group communication schemes proposed so far, where some schemes guarantees transparent communication among the agents. However, in mobile agent environments, we require new group communication schemes that consider topology changes caused by mobile agent migrations. Also, these group communication schemes should be secure in order for them to be practical. In this paper, we propose a secure group communication scheme using the hierarchical overlay ring structure of mobile agents. The proposed scheme uses the ring channel in order to cope adaptively with the change of ring topology. The ring channel has basic information for construction of the ring and is managed only by the mobile agent platforms. Therefore, each mobile agent need not directly handle the ring channel and it can perform group communication without any consideration on the change of the ring topology.

• Convergence Security Journal
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• v.22 no.1
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• pp.39-54
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• 2022

Recently, the importance of collecting, analyzing, and real-time sharing of various cybersecurity data has emerged in order to effectively respond to intelligent and advanced cyber threats. To cope with this situation, Korea is making efforts to expand its cybersecurity data sharing system, but many private companies are unable to participate in the cybersecurity data sharing system due to a lack of budget and professionals to collect cybersecurity data. In order to solve such problems, this paper analyzes the research and development trends of existing domestic and foreign cyber security data sharing systems, and based on that, propose a cybersecurity data sharing system model with a hierarchical structure that considers the size of the organization and a step-by-step security policy that can be applied to the model. In the case of applying the model proposed in this paper, it is expected that various private companies can expand their participation in cybersecurity data sharing systems and use them to prepare a response system to respond quickly to intelligent security threats.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.425-433
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• 2009

Spatial models suitable for describing the evolving random fields in climate and environmental systems have been developed by many researchers. In general, rainfall in South Korea is highly variable in intensity and amount across space. This study characterizes the monthly and regional variation of rainfall fields using the spatial modeling. The main objective of this research is spatial prediction with the Bayesian hierarchical modeling (kriging) in order to further our understanding of water resources over space. We use the Bayesian approach in order to estimate the parameters and produce more reliable prediction. The Bayesian kriging also provides a promising solution for analyzing and predicting rainfall data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.527-534
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• 1994

This paper presents a Bin-Picking method in which robot recognizes the positions and orientations of unoccluded objects at the top of jumbled objects placed in a bin, and picks up the unoccluded objects one by one from the jumble. A method using feasible region, painting, and hierarchical test is introduced for recognizing the unoccluded objects from the jumbled objects. The 3D information is obtained using the bipartite-matching method which finds the least difference of 3D by comparing vertexes of one camera with vertexes of the other camera, then hypothesis and test are done. The working order of unoccluded objects is made based on 3D, position, and orientation information. The robot picks up the unoccluded objects from the jumbled objects according to the working order. This all process continues to the empty bin.

• Transactions of Materials Processing
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• v.21 no.6
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• pp.366-371
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• 2012

Atomistic simulations have become useful tools for exploring new insights in materials science, but the length and time scale that can be handled with atomistic simulations are seriously limiting their practical applications. In order to make meaningful quantitative predictions, atomistic simulations are necessarily combined with higher-scale modeling. The present research is thus concerned with the development of a multi-scale model and its application to the prediction of the mechanical properties of body-centered cubic(BCC) iron with an emphasis on the coupling of atomistic molecular dynamics with meso-scale discrete dislocation dynamics modeling. In order to achieve predictive multi-scale simulations, it is necessary to properly incorporate atomistic details into the meso-scale approach. This challenge is handled with the proposed hierarchical information passing strategy from atomistic to meso-scale by obtaining material properties and dislocation mobility. Finally, this fundamental and physics-based meso-scale approach is employed for quantitative predictions of the mechanical response of single crystal iron.

• Journal of architectural history
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• v.8 no.3 s.20
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• pp.39-51
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• 1999

The purpose of this study is to establish the theory of the spatial composition that is 'The Structure of Relation' in Korean traditional houses. This study has been focused on the spatial composition of Hyangdan. The form composition is an element defining primitive functions and space and producing aesthetical effects, where 'quality as a substance' is not important but 'quality as a relation' is essential. Quality as a meaningful relationship comes from realization and regulation of visual attributes among form elements. Each form compositional element establishes the hierarchical structure logically with the entire order, In order for the quality of all form compositional elements to be clarified as a meaningful relationship logically, 'compositional concept' which combines a series of form elements into the grammatical dependence to a specific direction, has to be assumed. If the intrinsic relationship among a series of form compositional elements fails to confront with the 'contextual concept' which eventually indicates unique conditions for a place according to the refined compositional concept, the result of form composition never leads to a specific solution

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.153-160
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• 2010

MANET composed mobile nodes without central concentration control like base station communicate through multi-hop route among nodes. Accordingly, it is hard to maintain stability of network because topology of network change at any time owing to movement of mobile nodes. MANET has security problems because of node mobility and needs intrusion detection system that can detect attack of malicious nodes. Therefore, system is protected from malicious attack of intruder in this environment and it has to correspond to attack immediately. In this paper, we propose intrusion detection system based on rules in order to more accurate intrusion detection. Cluster head perform role of monitor node to raise monitor efficiency of packet. In order to evaluate performance of proposed method, we used jamming attack, selective forwarding attack, repetition attack.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1171-1181
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• 2014

Different power quality (PQ) disturbance sources can have major impacts on the power supply grid. This study proposes, for the first time, an early warning approach to identifying PQ problems and providing early warning prompts based on the monitored data of PQ disturbance sources. To establish a steady-state power quality early warning index system, the characteristics of PQ disturbance sources are analyzed and summed up. The higher order statistics anomaly detection (HOSAD) algorithm, based on skewness and kurtosis, and hierarchical power quality early warning flow, were then used to mine limit-exceeding and abnormal data and analyze their severity. Cases studies show that the proposed approach is effective and feasible, and that it is possible to provide timely power quality early warnings for limit-exceeding and abnormal data.

• IE interfaces
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• v.6 no.2
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• pp.53-65
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• 1993

This paper deals with the development of a software module for production planning and scheduling activities of an existing Flexible Machining and Assembly System (FMAS). The Production Planning Module uses the hierarchical and sequential scheme based on "divide and conquer" philosophy. In this module, routes are determined based on the production order, orders are screened, tools are allocated, and order adjustments are executed according to the allocated tools. The Scheduling Module allocates the resources, determines the task priority and the start and completion times of tasks. Re-scheduling can be done to handle unforeseen situations such as lumpy demands and machine breakdowns. Since all modules are integrated with a central database and they interface independently, it is easy to append new modules or update the existing modules. The result of this study is used for operating the real FMAS consisting of a machining cell with 2 domestic NC machines and a part feeding robot, an assembly cell with a conveyor and 3 robots, an inspection cell, an AGV, an AS/RS, and a central control computer.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.104-108
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• 2021

In order to improve performance in IoT, edge computing system, a memory is usually configured in a hierarchical structure. Based on the distance from CPU, the access speed slows down in the order of registers, cache memory, main memory, and storage. Similar to the change in performance, energy consumption also increases as the distance from the CPU increases. Therefore, it is important to develop a technique that places frequently used data to the upper memory as much as possible to improve performance and energy consumption. However, the technique should solve the problem of cache performance degradation caused by lack of spatial locality that occurs when the data access stride is large. This study proposes a technique to selectively place data with large data access stride to a software-controlled cache. By using the proposed technique, data spatial locality can be improved by reducing the data access interval, and consequently, the cache performance can be improved.