• Journal of the Korea Computer Industry Society
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• v.4 no.12
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• pp.965-974
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• 2003

Today's network consists of a large number of routers and servers running a variety of applications. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSs agent and a firewall agent which coordinate by CNP (Contract Net Protocol). The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls the execution of agents or a contractee, who performs intrusion detection. In the knowledge-based network security model, each model of simulation environment is hierarchically designed by DEVS (Discrete Event system Specification) formalism. The purpose of this simulation is the application of rete pattern-matching algorithm speeding up the inference cycle phases of the intrusion detection expert system. we evaluate the characteristics and performance of CNP architecture with rete pattern-matching algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.921-930
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• 2004

In this paper, a robust video transmission system is proposed. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domains, a version of turbo code, so-called as byte-aligned variable-length turbo code, is applied. Protection performance of the proposed turbo code is first evaluated by applying it to GOB-based variable-size ITU-T H.263+ video packets, where the protection level is statically controlled based on the joint source-channel criteria. This protection is then extended to support the adaptation of code ratio to best match the time-varying channel condition. The time-varying Rayleigh fading channel is modelled considering the correlation of the fading channel. The resulting performance comparison with the static turbo code as well as the conventional RCPC code clearly demonstrates the possibility of the proposed adaptation approach for the time-varying correlated Rayleigh-fading channel.

• The KIPS Transactions:PartC
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• v.13C no.6 s.109
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• pp.691-700
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• 2006

To support context-aware services in ubiquitous computing environments, there are required dynamic context managing, context reasoning and context modeling technologies. In previous researches, context services are designed using context ontology used in context aware middleware. So, context service cannot change the context ontology in execution time. In this paper, we propose a hierarchical ontology-based context management model and design a context-aware middleware based on this model for supporting active application adaptability and reflecting users' requirements dynamically in contextual changes. It also provides efficient support for inferencing, interpreting, acquiring and discovering various contexts to build context-aware services and presents a resolution method for context conflict which is occurred in execution of service. As the middleware is implemented on the OSGi framework, it can cause interoperability among devices such as computers, PDAs, home appliances and sensors. It can also support the development and operation of context aware services, which are required in the ubiquitous computing environment.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.35-46
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• 2012

As complexity of real-time systems is being increased ad hoc approaches to analysis of such systems would have limitations in completeness and coverability for states space search. Formal means using a model-based approach would solve such limitations. This paper proposes a model-based formal method for logical analysis, such as safety and liveness, of real-time systems at a discrete event system level. A discrete event model for real-time systems to be analyzed is specified by DEVS(Discrete Event Systems Specification) formalism, which specifies a discrete event system in hierarchical, modular manner. Analysis of such DEVS models is performed by Communicating DEVS (C-DEVS) formalism of a timed global state transition specification and an associated analysis algorithm. The C-DEVS formalism and an associated analysis algorithm guarantees that all possible states for a given system are visited in an analysis phase. A case study of a safety analysis for a rail road crossing system illustrates the effectiveness of the proposed method of the model-based approach.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.71-81
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• 2013

Recently, Korean Traditional House is being reconsidered as a alternative and eco-friendly residential housing. With these flows, government and industry actively studies the modernization and industrialization of Korean Traditional House. Apply for BIM as a way of modernization and industrialization of Korean Traditional House, research has been actively conducted. Korean Traditional House is building that is assembled by individual Component Therefore it is very useful for modernization of the Korean Traditional House to design Korean Traditional House With BIM. Which is the management technology that produces and distributes information of the architecture. But compared with the effect, the use of BIM is sluggish in the construction. Therefore, In this study after surveying about lowly using BIM on point of AEC(Architect-Engineer-Contract), the result is analyzed with AHP(Analytic Hierarchy Process). So the aim of this study is to offer the base to find the solution of the Affecting factors about lowly using BIM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.314-324
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• 2004

Recently, high-speed internet subscribers have grown continuously, and reached up to 10 millions. But existing network management that is responsible only for user access is confronted with many difficulties, since user access network(xDSL, Cable, B-WILL, and so on) has diversified and value added wired/wireless contents service has developed. In this paper propose the Agent based Inter Networking platform as object-oriented hierarchical system that can provide various service such as access QoS(Quality of Service), customized application service and security service according to user on demand. This system has divided into two parts(user agent and agent management system ＆ local and central management systems). Management system periodically receive status information such as bandwidth, download speed, delay, current service, and so on, and process them, then build a policy based on processed information. According to personal user profile that is generated by this policy, the customized service can be provided for users. And This system adopt the object-oriented modeling in case that system migration and integration, and implement a system that is robust and stable for security through hierarchical server system.

• Journal of the Korean Institute of Rural Architecture
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• v.18 no.1
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• pp.57-65
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• 2016

When the castle of the city was destructed from 1911 through 1915 in Cheongju, the city's spatial structure was reorganized and "Han-ok Housing", a dwelling site filled with Korean traditional houses, was newly formed around the former castle site. These days, the Han-ok housing in Seoun-dong, Cheongju in which elderly couples and senior citizens live is enclosed by modernized roads and three or four-story buildings, leaving the housing as an isolated island in the city block. Nonetheless, the Han-ok housing not only plays an important role in sustaining the historic and local identity of the city, but also offers environmental benefits in terms of daylighting and ventilation. The purpose of this study is to reorganize the housing suitable for those who currently live and recreate it by adding new functionality. Consequently, three strategies are established; the conservation of existing building through the improvement of existing facilities; the conversion of vacant buildings into a new use; and the creation of the urban mid-rise Han-ok housing at street sides. The first strategy has a significance in that the traditional building's single wing plan, small room sizes and lack of storages now cause great inconvenience for current life style. The second strategy also promotes the practical use of abandoned buildings through alterations and additions. Finally, the creation of the urban mid-rise Han-ok housing that is accomplished by the combination of reinforced concrete and wooden structure interacts with or respond to the city's development. As a result, this study for the adaptive reuse of Han-ok housing proves how the traditional properties can be maintained in a careful manner and how its creative reuse can be achieved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.145-155
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• 2010

In this paper, we suggest a fish drug domain ontology to show an associated information and hierarchy together through concept-relation and inference mechanism instead of keyword matching. First, we investigate competency questions from workers of fishery industry and then we derive concepts and terminologies. Next, we present a process of fish drug ontology modelling using Protege-OWL editor, which is an extension of Protege that supports the Web Ontology Language(OWL). Last, we suggest the user interface of semantic web-based fish drug information system to search easily associated informations of fish drug using this ontology. It is to provide an effective search method that fish disease manager, fish farmer, and students majoring in fisheries can confirm details of diseases, fish, and drug evaluations associated with fish drug within one screen without moving to another position.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.370-379
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• 2014

Recently, the interest in optical network with multifiber link is continuing to rise since the network traffic has been growing exponentially. However, growing traffic in network leads to increasing the energy consumption of the network equipment. In this paper, we propose a dynamic routing and wavelength assignment (RWA) algorithm based on V-like cost function and layered graph to improve energy efficiency in IP over WDM network with multifiber link. The V-like cost function is used to decide the fiber cost according to the number of used wavelengths. The layered graph with multifiber link is used to select the energy efficient route and wavelength. The proposed RWA algorithm is compared and analyzed with conventional algorithm in view of average power consumption and blocking probability through OPNET modeler.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.711-723
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• 2017

This paper proposes a flight control system for an organic flight array(OFA) which has a new configuration to consist of multi modularized ducted-fan unmanned aerial vehicles (UAVs). The OFA is able to apply to various missions such as indoor reconnaissance, communication relay, and radar jamming by using capability of hover flight. The OFA has a distinguished advantage due to reconfigurable structure to assemble or separate with respect to its missions or operational conditions. A dynamic modelling of the OFA is derived based on equations of motion of the single ducted-fan modules. In order to apply nonlinear control method, an affine system of attitude dynamics is derived. Moreover, the control system is composed of a back-stepping controller for attitude control and a PID controller for position control. Then the performance of the proposed controller is verified via a numerical simulation under wind disturbance.