• Information and Communications Magazine
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• v.15 no.7
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• pp.75-94
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• 1998

In this paper, HFC CATV networks are introduced. HFC CATV networks are currently considered as a most effective and plausible solution for subscriber access networks in the information superhighway, among others such as ADSL and B-WLL. The advantages of HFC CATV networks include its broad upstream and downstream channel bandwidths, much wider than PSTN's and its readiness. The HFC CATV networks are already well spread among the general subscribers in Korea. This fact will shorten the installation period and significantly reduce its cost. In addition, The structure and channel environment of the HFC CATV networks are introduced. At the same time, in this paper included are major problems in the HFC CATV networks and the solutions for these problems. Also discussed are data transmission, medium access control, IEEE802.14, and MCNS for standardizations. Moreover, additional telecommunications service activities in both Korea and other countries, using HFC CATV networks are also included. The topics which are covered in detail are the ones such as interoperation between HFC CATV networks and trunk line and the digital transmission performance test for the CATV networks. In the performance test, it is concluded that HFC CATV networks can satisfy the QoS for various additional services if the number of the subscribers in a cell is limited to less than 500 and other minor requirements are satisfied. Based on all these discussions and conclusions, HFC CATV networks are suggested in this paper for the subscriber access networks of the so called information superhighway.

• Journal of Korea Spatial Information System Society
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• v.2 no.1 s.3
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• pp.5-16
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• 2000

OGC(Open GIS Consortium) suggests the 'OpenGIS Simple Feature Specification for CORBA' which is the OpenGIS implementation specification for CORBA to specify standard interfaces for reuse and interoperation among distributed heterogeneous GIS resources in the CORBA distributed computing environment. An OpenGIS server that supports this implementation specification moat correctly implement all interfaces defined in the OpenGIS implementation specification to be interoperable with wrapped GISs efficiently. In this paper, we have designed and implemented an OpenGIS server based an object relational GIS, called GEUS that integrates GIS and database technologies to provide spatial data types and spatial operators from the DBMS engine level. In the CORBA distributed computing environment, clients can access geospatial data stored in GIS wrapped by the OpenGIS server through the standard interfaces defined in the OpenGIS implementation specification for CORBA. In addition, clients can use geospatial operation features provided by a back-end GIS and interoperate with other GISs.

• Journal of the Korea Society for Simulation
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• v.17 no.1
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• pp.43-52
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• 2008

The High Level Architecture(HLA) is the IEEE 1516 standard for interoperation between heterogeneous simulators which are developed with different languages and platforms. Run-Time Infrastructure(RTI) is a software which implements the HLA Interface Specification. With the development of time management service of RTI, it is necessary to consider an efficient design approach and an algorithm of Greatest Available Logical Time(GALT) computation. However, many time management services of existing RTIs have difficulty in modification and extension. Although some RTIs avoid this difficulty through modular design, they comply with not IEEE 1516 HLA/RTI but HLA 1.3. In addition, a lot of RTIs made use of well-known Mattern's algorithm for GALT computation. However, Mattern's algorithm has a few limitations for applying to IEEE 1516 HLA/RTI. This paper proposes a modular design and an implementation of time management service for IEEE 1516 HLA/RTI. We divided th time management service module into two sub-modules: a TIME module and a GALT module and used Mattern's algorithm improved for IEEE 1516 HLARTI. The paper also contains several experimental results in order to evaluate our time management service module.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.273-281
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• 2008

In a knowledge-information based society, effective management across IT industries, value of information and interoperation are more important than eyer before. Therefore, ITA/EA which helps to plan and manage IT systematically and effectively, was enacted and announced in 2005 and has been considered as an innovative IT management approach. Unfortunately, however, new standardization of ITA/EA has not fully discussed yet. How to successfully apply EA/ITA to IT is considered as the most urgent challenge and this study aims to find out the most effective method. To this end, it was emphasized that training systems for specialized experts must be operated systematically through 'standardization of terms and tasks' and 'standardization of manpower training' and certification of specialty must be newly established. In addition. it was strongly demanded that dual structure caused by mixed concepts between ITA and EA must be eliminated. At the same time. a new model for domestic standardization was suggested so that not only ITA/EA can be recognized as IT engineering but also professional engineers can accept ITA/EA as a scientific field. In summary, this study is intended to propose how to improve information management efficiency through ITA/EA.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.70-80
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• 2007

For supporting various mobile networks, this paper proposes a framework of distributed connection admission control, named SmartCAC. Especially, intelligent CAC operations are adopted in terms of interoperation between mobile nodes and mobile networks. This scheme does not need to correct information between networks. Basically vertical handover call can use guard channel that was reserved for handoff, because SmartCAC addresses the identification between vertical handover call and new call, delay and reliability as requirement of QoS for efficient connection control. The scheme also uses mobile terminal speed for network filtering. Especially an extended protocol is proposed to give different network states information to mobile nodes because there have been no ways for mobile nodes to compare the states of different networks. Sophisticated simulation study is performed in order to evaluate SmartCAC in terms of signaling cost. As a result, signaling cost of ours is up to 96% better than that of the existing scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.652-655
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• 2002

The next generation Internet Protocol IPv6 that is appeared to solve the exhausting problem is now widely deployed in a testbed or commercial site. To successfully deploy IPv6, interoperation with exist IPv4 hosts and routers and interactions with many IPv4 applications are more important. The NAT-PT (Network Address Translation-Protocol Translation) among IPv6 transition mechanism enables the communication between IPv4 and IPv6 host with translating IPv4 address and IPv6 address. But for DNS and FTP, another specific mechanism is needed when internet address is included in packet payload area. This paper describes the design and implementation of IPv6-support FTP-ALG, (Application Layer Gateway) to enable FTP service between IPv4 node and IPv6 node.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.132-135
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• 2002

In radio communication technology, SDR(Software Defined Radio) technology is emerging as a trendy technology for future. SDR is expected to change existing radio systems including central hardware. SDR is equipment that wireless parameters (frequency, modulation, additional service, power level, receive sensitivity, etc.) are controlled by software. In the world, equipments using the new technology are spreading. Not only equipments being imported but also local manufacturers are making this equipment, developing software and offering upgraded service. In the future, as SDR spreads and users choose the service, diverse equipments will be developed through competition and individual development. This diversity of equipment and services will introduce problems in compatibility and interoperation issues. So the government will have to make technical standard for SDR service and will have to make theses standards available to users and manufacturers alike. Therefore I am investigating the elements that can be used to establish these standards.

• Journal of the Korea Society for Simulation
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• v.26 no.2
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• pp.19-29
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• 2017

System Entity Structure/Model Base (SES/MB) enhances organizing model families and storing and reusing model components in the multifaceted system modeling. However, the real world can be described not only an individual system but also a collection of those systems, which is called system of systems (SoS). Because SES/MB has a limitation to simulate the SoS using HLA/RTI, an extended framework is required to simulate it. Therefore, this paper proposes System of Systems Entity Structure/Federate Base (SoSES/FB) for simulation in a distributed environment (HLA/RTI). The proposed method provides the library of federates (FB) and System of System Entity Structure (SoSES) formalism, which represents structural knowledge of a collection of simulators. It also provides a methodology for the development process of distributed simulation. The paper introduces the anti-missile defense simulation using the proposed SoSES/FB.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.117-125
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• 2003

IPv6 (IP version 6), which was standardized by the IETF (Internet Engineering Task Force) to cope with existing IPv4 problems, needs several approaches for interoperation with IPv4. The internetworking of IPv6 with IPv4 is an important key to the deployment of the next generation Internet. As the solutions to the transition mechanism, both tunneling and translator methods have been proposed. In this paper, we analyze functional elements for implementation design of a transition mechanism based on the NAT-PT (NAT-Protocol Translation), and propose an extension algorithm that uses ports for effective use of global IPv4 addresses. The algorithm presented in this paper is a method of combining NAT-PT with Port Translation mechanism. The algorithm does not assign an IPv4 address to the host that needs IPv4 address, but allocates a single temporary IPv4 address and a port number in order to identify host.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.71-81
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• 2014

It is an important issue to evaluate the effectiveness of chemical warfare through modeling and simulation(M&S) technology. In this paper, we propose the M&S methodology and environment for the chemical warfare for effectiveness analysis. In detail, for modeling perspective, we propose three fundamental component models according to their behaviors, which are a chemical weapon, a detecting device system, and an engaging unit system. Among proposed models, the chemical weapon and the detecting device system models are represented by engineering-level system models, whereas the engaging unit system model are described as an engagement-level system model. For simulation perspective, we apply a hybrid simulation environment using High Level Architecture (HLA) to interoperate with the proposed engineering and engagement-level models. The proposed M&S methodology and environment enables to evaluate the effectiveness of the chemical warfare system considering the doctrines, the performance of device or weapon, and weather factors. To verify the efficiency of the proposed methodology and environment, we experimented three categorized case studies, which are related with those considering factors.