• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.160-162
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• 2003

분산 시스템 상에서 SDR 소프트웨어 시스템을 구현하려면 재구성성과 유연성이 필요하다. 따라서 이를 충족시켜줄 수 있는 객체지향 컴퓨팅 기술이 필요하게 된다. 이러한 분산 객체 구조를 가능하게 하는 핵심은 CORBA 미들웨어이다. CORBA는 소프트웨어 버스로서 분산성와 이종성을 숨기고 분산 객체들이 유연하게 통신할 수 있게 해주는 핵심 역할을 담당한다. 분산 네트워크 환경 하에서 CORBA의 네이밍 서비스는 네임 서버에 저장한 논리적 이름을 통해서 객체의 위치 정보를 얻는다. 이 방식은 서버의 물리적인 위치 변화에 상관없이 객체의 위치 투명성을 제공한다. 본 논문에서는 SDR 시스템에서 클라이언트가 재구성을 위한 소프트웨어를 다운로드를 받기위해 서버의 구현객체에 논리적인 이름을 이용하여 접근을 가능하게 해주는 신뢰성 있는 CORBA 네이밍 서비스를 설계함으로써 SDR 시스템의 지역적 투명성을 지원하는 모델을 제안한다.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.19-24
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• 2005

Radio Frequency Identification (RFID) is a technology used to identify the physical objects and get information about the object on which the tag attaches from network. It is expected that RFID will lead IT market from human-oriented to object-oriented. Therefore, RFID technology and services will become wide-spread. But the system of RFID naming service is quite similar to the existing DNS facilities. So it has many weak points against to DDos attack. Furthermore if the MDS server Is under attack, there might be trouble of total RFID networks.In this paper, we propose a new detecting model to find attack traffic at local routers by using Management Information Base (MIB) which is optimized for RFID MDS server.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.233-235
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• 1999

공동저작 관리 시스템은 효율적인 공동저작을 위해 공유객체관리기능, 세션관리기능, 텔리포인팅(telepointing) 기능, 그리고 공동저작 인지(collaboration awareness) 기능들을 제공해야 한다. 이 중 공유객체관리기능은 저작자로 하여금 등록된 공유객체들을 편리하게 액세스 할 수 있도록 하고 저작에 필요한 공유객체들을 등록, 변경, 그리고 삭제할 수 있도록 함으로써 작업효율을 증대시킬 수 있는 핵심기능이다. 최근의 연구는 주로 등록된 공유객체의 변경 및 불필요한 정보전송으로 인한 작업지연, 그리고 공유객체 액세스 권한의 효율적인 관리를 위한 플로어 제어(floor control)에 그 초점을 맞추고 있으나 공유객체관리를 위한 기법이나 구조에 관한 연구는 미흡하다. 편리한 공동저작을 위해서는 분산환경의 특징상 가 저작자들의 시스템에 자연스럽게 분산되어 있는 공유객체들을 저작자나 공유객체들의 실제 위치에 상관없이 액세스할 수 있도록 하고, 저작자로 하여금 공유객체의 등록 시에 유일명 부여(unique naming)를 가능하게 하여 필요한 공유객체를 쉽게 검색할 수 있도록 해야 한다. 이를 위해 본 논문은 공유객체 디렉토리 서비스(shared-object directory service)를 제안한다. 공유객체 디렉토리 서비스는 일반 디렉토리(normal directory)와 세션 디렉토리(session directory)를 저작자에게 제공하여 공유객체의 등록시에 유일명 부여를 가능하게 하고 필요한 공유객체 검색을 용이하게 한다.

• Journal of Information Technology Applications and Management
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• v.17 no.1
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• pp.83-105
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• 2010

The competence of enterprise for managing information is evaluated not by the amount of information but by the quality of information such as response time, data consistency, and data correctness. The degradation of data quality is usually caused by the inappropriate process of managing the structure and value of stored data. According to the recent survey on the actual condition of data quality management, the correctness and consistency of data appeared to be the most problematic area among the six criteria of data quality management such as correctness, consistency, availability, timeliness, accessibility, and security. Moreover, the problem was more serious in case of small and medium-sized companies than large enterprises. In this paper, therefore, we attempt to propose a new data quality control methodology for small and medium-sized companies that can improve the correctness and consistency of data without consuming too much time and cost. To adopt the proposed methodology to real application immediately, we provided some scripts for as-is analysis and devised automation tools for managing naming rules of vocabulary, terminology, and data code. Additionally, we performed case study on the distribution service of a small-sized company to estimate the applicability of our tool and methodology.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.541-548
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• 2008

Today, GIS service requires not only a simple map visualization but also geographical information of each object. However, POI service provides simply geographical naming service only because of lacking in geographical information of objects. In addition, geographical space data representation functioning that is the basis for most GIS has not been standardized yet. In this paper, it is designed that POI DB that is hierarchical and user-oriented and it is constructed that GVP(GML Viewer POI) that is the basis of GML specification to overcome difference and incompatibility of map visualization. GVP adds POI DB in a 3-Layer structure to dBase file managing the information of SHP file attributes. Therefore, POI visualization enables hierarchical search, by providing POI information in directory-type grouping. Consisting of map visualization and POI visualization, GVP regenerates attributes in the form of individual objects and responds to user events immediately.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.67-73
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• 2008

Our research is aimed at developing an architectural frame-work of USN sensor network discovery service systems. The research is fo-cused on the four areas a survey of USN technology, development of a USN software model, development of the design space of the USN sensor network discovery service, and finally the architectural framework of the USN sensor network dicovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology, USN networking technology, and USN middleware along with the service platform, With respect to each technological division, domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research output To provide a means to analyze sensor network discovery services, we devel-oped the design space of the sensor network discovery services by exploring the scalability with respect to query scope, lookup performance, and resolution network.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.559-571
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• 2003

ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5B
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• pp.816-823
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• 2010

Recently research efforts for ubiquitous technology that includes RFID(Radio Frequency Deification and sensor networks are conducted very actively The architectural framework of the USN sensor network discovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology USN networking technology and USN middleware along with the service platform, With respect to each technological division domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research outputs. Boasted on the result of the survey we establish a USN software model that includes data sensing, sensor data storage sensor data storage sensor data naming and sensor feed name service. This main objective of this model is to provide a reference model for the facilitation of USN application developments.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.746-758
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• 2006

Many objects existing on wide area environments have the replication characteristics according to how to categorize using their own names or properties. From the clients' requests, the existing naming and trading services have not supported with the binding service for replicated solver object with the same service type. For this reason, we present an integrated model that can support the selection of replicated object and dynamic binding services on wide-area computing environments. This model suggests provides not only location management of replicated objects but also active binding service which enables to select a least-loaded object on the system to keep the balance of load between systems. In this purpose, constructing both the service plan and model for support solver object's binding with replication property on wide area computing environments has been researched. In this paper, we showed the test environment and analyzed the performance evaluation of client/server binding procedures via integrated binding service in federation model and verified our model under the condition to see whether load balance can be applied to our model. For the performance evaluation of suggested wide area integrated binding service federation model, evaluated the integrated binding service of each domain and analyzed the performance evaluation of process for non-replication object's under federation model environment. Also, we analyzed the performance evaluation of the federation model between domains for wide area environment. From the execution results, we showed the federation model provides lowers search-cost on the physical tree structure of network.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.69-76
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• 2009

Self healing systems are considered as cognation-enabled sub form of fault tolerance system. But our experiments that we report in this paper show that self healing systems can be used for performance optimization, configuration management, access control management and bunch of other functions. The exponential complexity that results from interaction between autonomic systems and users (software and human users) has hindered the deployment and user of intelligent systems for a while now. We show that if that exceptional complexity is converted into self-growing knowledge (policies in our case), can make up for initial development cost of building an intelligent system. In this paper, we report the application of AHSEN (Autonomic Healing-based Self management Engine) to in OKKAM Project infrastructure backbone cluster that mimics the web service based architecture of u-Zone gateway infrastructure. The 'blind' load division on per-request bases is not optimal for distributed and performance hungry infrastructure such as OKKAM. The approach adopted assesses the active threads on the virtual machine and does resource estimates for active processes. The availability of a certain server is represented through worker modules at load server. Our simulation results on the OKKAM infrastructure show that the self healing significantly improves the performance and clearly demarcates the logical ambiguities in contemporary designs of self healing infrastructures proposed for large scale computing infrastructures.