• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.661-669
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• 2004

As a large number of distributed systems becoming more popular, interoperability, portability and security are becoming major concerns of modern computing. CORBA and object-oriented database which provide transparency of network and database are increasingly being used as the basis for distributed system to solve these problems. The two methods can help accomplish assurance of security by using a method-based access control technique or an attribute-based access control technique. These methods also enhance the unavailability or inefficiency caused by the delay of access process and bottleneck of the network due to the complex instance-based access control. We propose a security model on the type information based access control system that can enhance both security and availability by separating the functions delivered from CORBA and object-oriented databases. We apply the access control model specifically to enhancement of security system and also perform a test to verify the security and availability of our model.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.771-781
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• 1999

오늘날의 컴퓨팅 환경은 통신 네트워크의 복잡성과 다양한 멀티미디어 서비스 처리를 위해 객체지향 기술을 분산 시스템에 도입하고 통신망을 소프트웨어 계층적 모델로 구조화한 개방형 정보 통신망 구조 연구가 활발히 진행되고 있다. 본 논문은 분산환경에서 멀티미디어 스트림 데이타를 전송하기 위한 아키텍쳐에 관한 모델의 설계 및 구현에 관한 것으로 분산 환경에서 멀티미디어 스트림 데이타를 효율적으로 전송할 수 있는 구조를 제시하고 있다. 설계한 구조는 Point-to-Point와 멀티캐스트를 지원하며 컴퓨터 통신망에서 멀티캐스트 연결을 효율적으로 관리하고 추후 기능 확장 및 기능 변경이 용이하도록 모듈화하고 유연성을 가지는 연결 관리 구조를 설계하고 구현하였다. 신호기능은 CORBA(Common Object Request Broker Architecture)의 ORB를 이용하여 실현하였으며, 데이타 전송 기능은 TCP/IP연결을 이용하였다. 이렇게 신호처리 부분과 데이타 전송 부분을 독립적으로 만들어서 하부망 기술에 독립적인 연결 관리 구조를 채택하고 있으므로 향후 다른 환경에서도 신호처리 부분을 그대로 적용할 수 있다. 분산 객체 개념을 적용하여 연결 관리 기능을 분산 객체화 하였으며 각 분산 객체간 인터페이스를 OMG(Object Management Group) IDL(Interface Definition Language)로 정의함으로써 유연성을 갖도록 하였다.AbstractThis paper proposes communication service architecture to support dynamic communication configuration and multiple connection management which are required to handle a variety of multimedia multicast application. Our communication service architecture was designed to fulfil the objectives as the following:- To build a common networking system for various multimedia multicast services- To build a platform for rapid service development and provisioning- To provide service networking independent on transport network technologiesWe implemented communication service architecture based on Common Object Request Broker Architecture (CORBA) for multimedia multicast applications. Our communication service architecture is distributed and object-oriented for extensibility and easy modification. The interfaces between the distributed objects are specified in (Object Management Group) OMGs Interface Definition Language.

• Journal of Computing Science and Engineering
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• v.1 no.1
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• pp.56-73
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• 2007

Demands have been growing in safety-critical application fields for producing networked real-time embedded computing (NREC) systems together with acceptable assurances of tight service time bounds (STBs). Here a service time can be defined as the amount of time that the NREC system could take in accepting a request, executing an appropriate service method, and returning a valid result. Enabling systematic composition of large-scale NREC systems with STB certifications has been recognized as a highly desirable goal by the research community for many years. An appealing approach for pursuing such a goal is to establish a hard-real-time (HRT) component model that contains its own STB as an integral part. The TMO (Time-Triggered Message-Triggered Object) programming scheme is one HRT distributed computing (DC) component model established by the first co-author and his collaborators over the past 15 years. The TMO programming scheme has been intended to be an advanced high-level RT DC programming scheme that enables development of NREC systems and validation of tight STBs of such systems with efforts far smaller than those required when any existing lower-level RT DC programming scheme is used. An additional goal is to enable maximum exploitation of concurrency without damaging any major structuring and execution approaches adopted for meeting the first two goals. A number of previously untried program structuring approaches and execution rules were adopted from the early development stage of the TMO scheme. This paper presents new concrete justifications for those approaches and rules, and also discusses new extensions of the TMO scheme intended to enable further exploitation of concurrency in NREC system design and programming.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.340-342
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• 2003

Location based services based on positions of moving objects are expanding the business area gradually. The location is included all estimate position of the future as well as the position of the present and the past. Location based routing service is active business application in which the position information of moving objects is applied efficiently. This service includes the trajectory of past positions, the real-time tracing of present position of special moving objects, and the shortest and optimized paths combined with map information. In this paper, we describes the location based routing services is extend in distributed web GIS environment. Web GIS service systems provide the various GIS services of analyzing and displaying the spatial data with friendly user - interface. That is, we propose the efficient architecture and technologies for servicing the location based routing services in distributed web GIS environment. The position of moving objects is acquired by GPS (Global Positioning System) and converted the coordinate of real world by map matching with geometric information. We suppose the swapping method between main memory and storages to access the quite a number of moving objects. And, the result of location based routing services is wrapped the web-styled data format. We design the schema based on the GML. We design these services as components were developed in object-oriented computing environment, and provide the interoperability, language-independent, easy developing environment as well as re - usability.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.36.6-36
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• 2001

The problem of robot navigation and control is a complex task. Its complexity and characteristics depends on the characteristics of the environment robot inhabits, robot construction (mechanical abilities to move, sense) and the job the robot is supposed to do. In this paper we propose a hybrid programming approach to mobile robot navigation and control in an indoor environment. In our approach we used declarative, procedural, and object oriented programming paradigms and we utilized some advantages of our distributed computing architecture. The programming languages corresponding to the paradigms we used were C, C++ and Prolog. In the paper we present some details of our mobile robot hardware and software structure, focusing on the software design and implementation.

• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.975-983
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• 1998

In these days, information communication systems are based on both open distributed computing technologies and object-oriented techniques like inheritance, encapsulation and object reuse to support various system configuration and application. As information systems are interconnected through unsecure networks, the need for the secure information exchange is more critical than before. In this paper, we have designed and implemented a transparent CORBA-basce Security infrastructure with authentication, security context association, access control and security information management to support a secure applications in distributed object environment. SESAME Ver. 4 was adopted as an external security service to manage user privilege attributes and to distribute keys for data encryption, decryption and integrity. Using filter and transformer with an interface to Object Request Broker, it provides a transparent security service to applications. The filter objects are special classes that allow additional parameters to be inserted into messages before they are sent and removed just after they are received. The transformer objects are special classes that allow direct access to the byte stream of every messages for encryption and decryption before it is sent and just after it is received. This study is to implement the access control interceptor(ACI) and the secure invocation interceptor(SII) of secure ORB defined in CORBA using filter and transformer.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.758-770
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• 1999

최근 급속한 네트워크 기술의 발달로 이들에 대한 관리의 필요성이 제기되었고 이를 위해 SNMP와 CMIP등과 같은 표준이 등장하여 사용되어 왔다. 그러나 점점 더 다양하고 복잡한 네트워크가 형성되자 이들에 대한 효율적인 관리가 필요하게 되었다. 현재, TMN은 개념에 있어서 보편성 및 가장 일반화된 관리개념이며 최종적으로 도달할 네트워크 관리 개념을 포함하고 있다. CORBA는 분산환경에서 응용프로그램을 쉽게 구현할 수 있는 기반을 제공하고 있다. 따라서 이러한 두 가지 기술을 접목한 CORBA와 TMN을 통합하고자 하는 많은 연구가 진행되고 있다. 본 논문에서는 현재의 CORBA/TMN 통합에 대한 연구를 바탕으로 효율적인 네트워크 통합 관리 구조를 정의하고 TMN의 기능중 Alarm Surveillance를 구조에 맞춰 구현하였다. 구현된 Alarm Surveillance System은 다양한 대리자들로부터 보고되는 여러 형태의 Alarm 정보에 대해, 처리 및 운용자에 대한 보고수행 등을 일관성 있게 처리하고 있는 것을 보여주고 있다. 따라서 제시된 Alarm Surveillance System은 사용자에게 일관성 있는 관리행위를 제공함으로써 다양한 관리구조가 적용된 복잡한 네트워크 관리를 제공할 수 있다. 또한 전체 네트워크로부터 필요한 통계분석을 위한 자료 수집 등의 편의를 제공할 것이다.Abstract Recently, due to the rapid development of network technology, the need for the network management appeared. So two representative standardards, SNMP and CMIP, have been applied to many network management system. But the more complex and vaious network are constructed, the demand for more efficient network management technology grew bigger. Currently, TMN technology is beginning to be widely applied to the management of networks. CORBA has been widely adopted for developing distributed systems in many areas of information technology. CORBA provides the infrastructure for the interoperability of various object-oriented management applications in a distributed environment, and, recently there have been world-wide research for the integration of CORBA within a TMN framework. Many attempts have been made to enable network management using CORBA techonology and some are working on already. This paper defines the architecture for integrated network management based on current CORBA/TMN integration technologies and then presents the design and implementation for alarm surveillance system which was applied to the defined architecture. The prototype implementation was done using IONA orbix. The proposed integrated network management framework will provide users with consistent management operations and ability to manage complex and various networks and to gather statistical data from those networks.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.329-334
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• 2018

Web services are standardized software technologies that enable interoperability of operating systems and programming languages through networks and related standards. Web services are distributed computing services that provide and discover services making it possible to access various services. Since the search method of web service considers only the functional aspect, it has a limitation on user-oriented search when selecting a service. In order to solve these problems, this study proposes an automatic IoT information generation tool, and provides IoT extension information when searching a web service, thereby improving the problem so that a suitable service can be selected for a user. Automatic IoT extension information generation tool proposed in this study collects and stores various information generated in the process of sensing, networking, and information processing by collaborating autonomously in a distributed environment of user, object, and service. The proposed method supports the service search suitable for the user by providing the information generated by the user as extended information when searching the web service. The proposed method can be applied to the 4th industry sector to provide a customized service that meets various environment requirements.

• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.5-18
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• 1999

Recently, the necessity of automatic knowledge extraction from spatial data stored in spatial databases has been increased. Spatial data mining can be defined as the extraction of implicit knowledge, spatial relationships, or other knowledge not explicitly stored in spatial databases. In order to extract useful knowledge from spatial data, an object management system that can store spatial data efficiently, provide very fast indexing & searching mechanisms, and support a distributed computing environment is needed. In this paper, we designed and implemented an open object management system for spatial data mining, that supports efficient management of spatial, aspatial, and knowledge data. In order to develop this system, we used Open OODB that is a widely used object management system. However, the lark of facilities for spatial data mining in Open OODB, we extended it to support spatial data type, dynamic class generation, object-oriented inheritance, spatial index, spatial operations, etc. In addition, for further increasement of interoperability with other spatial database management systems or data mining systems, we adopted international standards such as ODMG 2.0 for data modeling, SDTS(Spatial Data Transfer Standard) for modeling and exchanging spatial data, and OpenGIS Simple Features Specification for CORBA for connecting clients and servers efficiently.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.39-39
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• 2012

Data assimilation techniques have received growing attention due to their capability to improve prediction in various areas. Despite of their potentials, applicable software frameworks to probabilistic approaches and data assimilation are still limited because the most of hydrologic modelling software are based on a deterministic approach. In this study, we developed a hydrological modelling framework for sequential data assimilation, namely MPI-OHyMoS. MPI-OHyMoS allows user to develop his/her own element models and to easily build a total simulation system model for hydrological simulations. Unlike process-based modelling framework, this software framework benefits from its object-oriented feature to flexibly represent hydrological processes without any change of the main library. In this software framework, sequential data assimilation based on the particle filters is available for any hydrologic models considering various sources of uncertainty originated from input forcing, parameters and observations. The particle filters are a Bayesian learning process in which the propagation of all uncertainties is carried out by a suitable selection of randomly generated particles without any assumptions about the nature of the distributions. In MPI-OHyMoS, ensemble simulations are parallelized, which can take advantage of high performance computing (HPC) system. We applied this software framework for several catchments in Japan using a distributed hydrologic model. Uncertainty of model parameters and radar rainfall estimates is assessed simultaneously in sequential data assimilation.