• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.407-412
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• 2002

A FR-ATM interworking function that has FR and ATM interfaces, should guarantee the QoS of both frame relay and ATM networks. The IWF requires the policing mechanisms for FR and ATM respectively, and needs to map the traffic parameters each other. In this case, traffic parameter mapping and policing function are performed independently. In the aspect of FR traffic policing, this function degrades processor performance if it is worked by software, or includes additional hardware function. The best way to solve this is to integrate this function into ATM function because ATM is performed by well defined hardware already. In this paper we propose the integrated traffic control mechanism. That is, frames are segmented to cells first, and then policing mechanism is applied to the cells to guarantee the FR QoS. Therefore proper policing algorithm is essential to the integrated FR traffic mechanism. The evaluations are done with simulations in comparison of existing FR algorithms, ATM VBR and GFR policing algorithms, and the proposed algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.4
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• pp.10-21
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• 2003

Recently, the optical subscriber interface module uses the high performance network processor to quickly develop new application services such as MPLS, VPN, RPR and EPON with a short time-to-market. Although a number of vendors are developing the network processor at 2.5Gbps, only the IBM NP4GS3 can provide packet processing with wire-speed at 2.5Gbps. IBM NP4GS3, however, uses its unique speed DASL interface instead of CSIX-Ll interface, which has standardized by M: Forum currently Therefore, we implement an interconnection mechanism to use the switch fabric with CSIX-Ll interface. In this paper, we suggest the architecture and a packet control mechanism supporting interconnection between IBM NP4GS3 DASL and CSIX-Ll switch interface using the common IBM UDASL ASIC and XILINX FPGA.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.651-661
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• 2016

최근의 디지털 사이니지는 대형 고해상도 디스플레이를 이용해 사용자에게 초고해상도 파노라마형태의 볼거리를 제공하거나 사용자와 인터렉션 등을 통해 맞춤형광고를 제공하는 등 다양한 형태로 발전하고 있다. 또 개방형 디지털 사이니지의 발전과 함께 대형 멀티 사이니지를 이용한 초고화질 영상콘텐츠를 다양한 서비스 단말장치의 연동과 웹기반의 상호운용성을 갖춘 관리시스템이 활발히 연구될 것으로 보인다. 본 논문에서는 수십대에서 백여대 이상의 고해상도 디스플레이를 연동하여 초고해상도 영상표출의 기술의 구현방안과 정형화된 영상 해상도가 아닌 초고화질 영상의 개별 콘텐츠에 대한 동기화 시키는 기술을 이용하여 멀티 콘텐츠 플레이 단말기에서 고해상도 영상을 Play Sync하는 기술을 연구한다.

• Journal of KIISE:Information Networking
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• v.33 no.2
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• pp.156-164
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• 2006

The SCTP (Stream Control Transmission Protocol) implementation with the DAR (Dynamic Address Reconfiguration) extension is called the mSCTP (Mobile SCTP) that is proposed recently for mobility support in transport layer. The mSCTP does not satisfy short handover latency for real-time applications and it has no specific handover decision mechanisms. In this paper, we propose fast handover schemes for mobile nodes that are moving into different subnet using pre-acquisition RA (Router Advertisement) and L3 trigger for improving handover performance. Furthermore, we introduce three specific methods which are RA cache, FMIPv6 (Fast Handovers for Mobile IPv6) and dual interface and how proposed scheme can be interoperated with handover process respectively. Finally, we show two experimental results which are the mSCTP and the mSCTP using FMIPv6 on Linux platforms. Experimental results show that handover performance is improved with reducing the time of receiving RA which takes most of total handover latency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1051-1058
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• 2010

Mobile IP (MIP) and SIP are considered as important technologies to provide the macro mobility in the next generation mobile convergence networks which have heterogeneous access networks. Typically, MIP and SIP are more suitable for the non-real-time TCP connections and the real-time RTP/UDP sessions respectively, hence a handset which uses both of these sessions should simultaneously apply MIP and SIP to perform the efficient mobility management. Existing multi-layered mobility management schemes focus on the signalling order of each protocol. However, simple combining of two protocols cannot provide the performance enhancement of the mobility management. In this paper, a novel multi-layered mobility management algorithm using the combination of SIP and fast MIPv6 (FMIPv6) is proposed. FMIPv6 and SIP mobility is simultaneously performed to reduce the service interrupt time and to guarantee QoS requirement. The delay model is defined to analysis the performance of the algorithm and the simulation results show the performance of the proposed algorithm.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.157-166
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• 2009

There is a growing interest in ubiquitous-related research and applications. Among them, GPS-based LBS have been developed and used actively. Recently, with the increase of large size buildings and disastrous events, indoor spaces are getting attention and related research activities are being carried out. Core technologies regarding indoor applications may include 3D indoor data modeling and localization sensor techniques that can integrate with indoor data. However, these technologies have not been standardized and established enough to be applied to indoor implementation. Thus, in this paper, we propose a method to build a relatively simple 3D indoor data modeling technique that can be applied to indoor location based applications. The proposed model takes the form of 2D-based multi-layered structure and has capability for 2D and 3D visualization. We tested three prototype applications using the proposed model; CA(cellular automata)-based 3D evacuation simulation, network-based routing, and indoor moving objects tracking using a stereo camera.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.217-225
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• 2017

A study proposes possibility of new IoT measuring system blended with a smart device. The research serves the best cultivation information for domestic fruit's enhancement of competitive power and also develops a glucose measuring system by which people manage fructose with the mobile device. The mobile glucose tester is designed with a form of accessory which has high portability and utility because the product connects an existing analogy refractometer to the smart phone. You can check the glucose rates data by commodity, region, and season then save measurement results with server in real time for an exclusive application. It's possible to serve the glucose map, graph, and data list through the web service. This is very useful to do collect, analyze, and process the glucose data.

• Spatial Information Research
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• v.11 no.2
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• pp.119-130
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• 2003

Since GIS strategic implementation plan was prepared in 1995, Seoul Metropolitan Government (SMG) has implemented the distributed GIS at department level, which prevents various SMG organizations from data-sharing and its common utilization. To solve those problems due to the fragmented GIS structure, SMG developed an action plan for the evolution of enterprise GIS with Spatial Data Warehouse (SDW). In this context, this paper initially analyzed the conceptual architecture of SDW structure and then provided the following guidelines for 1) determining the common GIS data and framework data stored at SDW to satisfy the demand for various GIS data from many SMG departments and sub-organizations, 2) developing the data synchronization process and techniques to make effective data-sharing possible, and 3) making an action plan for enterprise GIS of other self-governmental organizations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.3
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• pp.59-72
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• 2017

As the part of study which handles the measure to use the individual vehicle information of taxi GPS data on signal controls in order to overcome the limitation of Loop detector-based collecting methods of real-time signal control system, this paper conducted series of evaluations and improvements on link travel time, queue vehicle time estimates and traffic condition decision algorithm from the research introduced in 2016. considering the control group and the other, the link travel time has enhanced the travel time and the length of queue vehicle has enhanced the estimated model taking account of the traffic situation. It is analyzed that the accuracy of the average link travel time and the length of queue vehicle are respectably both approximately 95 % and 85%. The traffic condition decision algorithm reflected the improved travel speed and vehicle length. Smoothing was performed to determine the trend of the traffic situation and reduce the fluctuation of the data, and the algorithms have refined so as to reflect the pass period on overflow judgment criterion.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.3-8
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• 2016

Wireless networks have evolved to the appearance of heterogeneous wireless networks(HetNet), where various networks provide data services with various data rates and coverage. One of technical issues for HetNet is efficient utilization of radio resources for system performance enhancement. For the next generation wireless networks, energy saving has become one of key performance indices, so energy-efficient resource management schemes for HetNet need to be developed. This paper addresses an energy-efficient scheduling for HetNet in order to improve the energy efficiency while maintaining similar system throughput as existing scheme, for which an energy-efficient scheduling that energy efficiency factor is included. Simulation results show that the proposed scheme achieves the reduction of energy consumption while admitting limited ragne of throughput degradation in comparison with the conventional proportional fair scheduling.