• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.83-92
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• 2005

Telematics is a wireless data communication system that provides various information services for driver's the safety or entertainment, and it makes drivers possible to use those services in the moving space, as if he/she is at home or at office. As telecommunication technology develops and Telematics market grows larger, standard platform for the intelligent telematics is required. This paper describes the structure and module control design of the intelligent telematics that recognizes driver's needs and pushes customized services to the driver at real-time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.87-89
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• 2017

In this paper, we propose a multi-band network selection (MNS) system, which determines and seamlessly connects to the desired available communication band based on user preferences and network environments. The MNS system employs MNS server in the middleware layer which communicates with clients in order to combine and manage heterogeneous networks efficiently. In addition, we define a system architecture and function modules of the MNS system. The MNS system monitors availability in each communication band and updates the network status information table which is applied to determining the best available network. It is expected that the MNS system can be applied to the next generation maritime networks and communication infrastructure of e-navigation.

• The KIPS Transactions:PartD
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• v.8D no.3
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• pp.193-202
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• 2001

Currently, the components of the GIS have been physically run on a stand-alone system. With rapid advances in internet technology, GIS users require that they are able to not only access they heterogeneous and remote GIS database as well as their own information, but also share them. However, these GIS have the defects that can not handle formats different from own data format. Therefore, in this paper, we propose to integrate the components of the heterogeneous and remote GIS using CORBA in order to solve these problems, which is a distributed object technology, the mediator and wrapper technology in client and server layers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1290-1300
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• 2016

Recently, various middle box services have been developed and applied to provide network functions to end nodes of the network. Especially, network virtualization is increasingly proceeding by applying the virtualization technologies of cloud computing field to network field, and network platforms for various flexible services are being developed to connect among the virtual network devices. Carrier-grade Network Address Translation (CGNAT) is also one of these flexible network services. This paper designs and implements the DPDK-based CGNAT framework that provides flexibility and maximizes address translation throughput. Our framework achieves 15.5 times higher throughput than the address translation service by Linux kernel.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.203-210
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• 2004

A new research of geographic information system has been focused on an open architecture, interoperability and extensibility in their design. In order to process huge data, multidimensional data and heterogeneous geographic format data, these research move away from monolithic system to open structure system managing application layer and user interface layer. Nowadays, many developers have used CORBA middleware for the OGIS systems. However, CORBA middleware has some problems that support only a point-to-point communication and takes a long time to transfer sever data to client. Thus, in this paper, we propose a method on modifying a point-to-point communication and implement the efficient communication method. The proposed method that transfer data from sever to client in one connection support a group communication and reduce a transfer time delay.

• Journal of Internet Computing and Services
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• v.3 no.4
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• pp.11-18
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• 2002

The IP multicasting service system based on IGMP(Internet Group Management Protocol) is the receiver initiated multicasting system that all receivers must join to and leave from the server of multicasting service. The IGMP is less effective and reliable to apply the education system that all computers of students ore synchronized a teacher's computer. A proposed middle-ware in this paper provides the reliable data transferring and the server initiated multicasting system that client as student's PC is controled by a multicasting server as teacher's PC, This middle-ware is consisted with two major component, The one is the group manager that handle the status informations of members in each group. Another is the reliable sender/receiver that has The transmission protocol based on NAK message and flow control. As the results of the test that 22khz digital voice data and 1024$\times$768 24bit color image data were tested for 30 PCs connected with 100baseT, the voice data was completely without error transferred and the image data was successfully transferred with 0.004% retransmit rate under 2 frames/sec load.

• 한국IT서비스학회:학술대회논문집
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• 2008.05a
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• pp.425-430
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• 2008

USN의 발전으로 인해 인간 중심의 정보화 사회에서 사물 간에도 정보들을 유기적으로 결합하여 활용하는 유비쿼터스 컴퓨팅 사회로 급격히 변모하고 있다. 이러한 유비쿼터스 컴퓨팅 인프라를 성공적으로 구축하기 위해서는 센서노드에 대한 기술의 발전과 함께 USN 미들웨어에 대한 연구가 필요하다. USN의 핵심기술 중 하나인 USN 미들웨어는 시스템 소프트웨어로써 USN 응용에서 USN 계층의 자원과 데이타를 쉽게 활용할 수 있도록 다양한 기본 서비스를 제공한다. USN 디렉토리 서비스는 이와 같은 USN 미들웨어의 핵심 컴포넌트로서 USN 응용이 필요로 하는 USN 자원에 대한 정보를 검색하는 기능을 수행한다. 분산된 USN 자원에 대한 메타데이타의 효율적인 검색은 분산된 환경에서의 USN 디렉토리 서비스의 핵심요소이며 최근 이에 대한 연구가 보이고 있다. 분산 USN 디렉토리 서비스에서의 메타데이타 검색 모델은 크게 중앙 집중식(Centralized) 모델, 계층식(Hierarchical) 모델, P2P(Peer-to-Peer) 모델이 있다. 그러나 현재 메타데이타 검색 모델에 대한 연구는 원하는 메타데이타를 찾기 위한 서버 검색 회수만을 대상으로 하고 있으며 실제 단말 간 응답시간에 영향을 미치는 지연시간은 고려하지 않고 있다. 본 논문은 실제 단말 간 응답시간에 영향을 미치는 검색회수와 지연시간을 고려한 하이브리드 모델을 제안하고, 하이브리드 모델이 계층 모델에서 검색 시 불필요한 검색횟수의 증가와 P2P 모델의 광범위한 지역에서 응답시간이 증가하게 되는 단점을 개선할 수 있음을 보인다.

• Korean Journal of Remote Sensing
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• v.25 no.4
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• pp.367-374
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• 2009

Recently, new GIS applications such as gee portal and spatial data infrastructure are emerging. These are related to web computing techniques or methodologies based on web 2.0 paradigm, open API of portal, open source GIS, and international GIS standards which are independently on developing. The product of these applications can be realized in the linkage of those components. In this study, a case implementation concerning linkage with Google maps API and open source middleware named Deegree is carried out, and the results are discussed for open source uses in geo portal. Open source middleware supports various levels and types of OGC standards, so that it enables web publishing in the several web standard formats and data exchanges and interoperable uses between external database servers. Also the (unction extensions and the multi tier-based architecture within geo portal for specific purpose are possible.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.653-658
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• 2023

In systems like the combat management system of a naval ship or smart city of civilians, where many sensors and actuators are connected, the middle-ware DDS (Data Distribution Service) is mainly used to transmit large amounts of data. It is scalable and can effectively respond to the increase in sensors or equipment connected to the system in the future. The engineering control system (ECS), which plays an important role similar to the combat management system of a naval ship, still uses Server-Client model with industrial protocols such as Modbus and CAN (Controller Area Network) bus, to transmit data, which is unfavorable in terms of scalability. However, as automation and unmanned systems advance, more sensors and actuators are expected to be added, necessitating substantial program modification. DDS can effectively address such situations. The purpose of this study is to confirm the development possibility of an integrated monitoring and control system of a ship by using OpenDDS, which follows the OMG (Object Management Group) standard among the middle-ware DDS used in the combat management system. To achieve this goal, field equipment simulators and an ECS server were configured to perform field equipment data input/output and simulation using DDS was performed. The ECS prototype successfully handled data transmission, confirming that DDS is capable of serving as the middle-ware for the ECS of a ship.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.233-241
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• 2018

Recently, integrated railway safety monitoring and control system, which is a convergence system based on data distribution service for railway safety monitoring and control, is under development. It collects safety data of vehicle, signal, power and safety monitoring facilities in real time and adopts communication middleware based on distributed service for mass data processing. However, in the case of a server device used as an existing control server, the performance of the distributed service middleware can not be exhibited due to low hardware performance due to safety reasons. In the safety control system, 200,000 packets per second were set as the transmission target, but the performance test of the LAB was not satisfied. In this paper, we analyze the characteristics of railway data to improve the data collection performance of existing equipment and apply DDS-based streaming transmission method to the data model of signal facilities and vehicle facilities with large packet amount according to the analysis result. As a result, it was confirmed that the throughput was improved about 30.4 times when the hardware performance was the same. We plan to improve the data processing performance by applying it to real-time railway safety integrated monitoring and control system in the future.