• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.131-136
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• 2021

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, a real-time EtherCAT master is implemented on Linux operating systems and its performances are evaluated. To enhance the real-time capability of mainline Linux kernel, Xenomai is applied as a real-time framework and an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on it. Unlike other studies, the real-time performance of the EtherCAT master is evaluated at the output of the network interface card, so that the evaluation results include all possible effects from the EtherCAT master system. The implemented EtherCAT master can send and receive packets up to 20KHz control frequency with low jitter, even in stressed condition.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.26-32
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• 2022

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, an EtherCAT master is implemented on an embedded board with Arm based 64-bit quad-core processor and its jitter performance is evaluated at the output of the network interface to include all the effects of the entire system in the results. For the EtherCAT master system, an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on PREEMPT_RT patched Linux operating system for real-time operation. The results show that the jitter performance is comparable to that of Xenomai-based master and the EtherCAT master with two master instances has similar jitter performance to the EtherCAT master with one master instance.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.684-687
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• 2009

본 논문에서는 iSCSI 기반 IP 스토리지를 이용하여 IPTV Set-Top-Box에서 PVR 재생 및 저장에 적합한 네트워크 스토리지 구조를 제안한다. 제안된 네트워크 스토리지는 멀티미디어 재생 성능 향상 및 효율적인 데이터 관리를 위하여 Content-aware 선반입, 스토리지 형상 관리 기법을 제안하고 DES 알고리즘을 기반으로 사용자인증이 가능 하도록 설계하였다. 제안된 네트워크 스토리지를 SMP8634기반 임베디드 보드에서 리눅스 2.6.15, 100Mbps Ethernet 환경에서 성능을 평가한 결과 HD급 영상을 충분히 재생할 수 있음을 확인하였다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.303-305
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• 2002

SSTF(Samsung Superconducting Test Facility) has been constructed at Samsung Advanced Institute of Technology to test the KSTAR(Korea Superconducting Tokamak Advanced Research) superconducting magnets and conductors. The SSTF DAC(Data Acquisition and Control) system basically consists of VME I/O modules, host PCs, and Ethernet links. VxWorks is used for the real-time OS of the VME IOC(Input/output Controller). EPICS (Experimental Physics and Industrial Control System) provides a software architecture for the communication between IOCs and host PCs. For the efficient management of measured data, the database management programs through NFS(Network File System) have been developed and successfully operated. In this paper, the current status of the SSTF DAC system, DBMS(DataBase Management System), recent test results, and future plans are presented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.3
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• pp.289-294
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• 1986

In this paper, we describe the development of an NIU (network interface unit) hardware for sharing computer resources and exchanging haigh-speed information between information systems distributed in a local area. The NIU designed and implemented in accordance with Ethernet specifications is operating normally with the upper layer software. Modular design makes it simple to change or expand the functions of the NIU. The NIU's are connected to 10Mbps coaxial cable through transceivers. In addition, a system and a design specifications for the NIU of a broadband LAN based on the K-LAN NIU are porposed.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.11-16
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• 2023

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, without operating system, we have implemented an EtherCAT master with an open source EtherCAT master stack SOEM on STM32 Nucleo-144 board with an STM32F767 microcontroller. And its jitter performance has been evaluated at the output of the network port to include all the effects of the entire system in the results. The results show that the implemented EtherCAT master has precise control performance for control frequencies from 1KHz to 8KHz and relatively superior jitter performance compared to the EtherCAT masters with real-time patched Linux operating system.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.709-716
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• 2005

QoS is an important requirement of the FTTH (Fiber To The Home) subscriber in access network using E-PON (Ethernet Passive Optical Network). In this research, we describe the structure of the access network and propose a bandwidth guarantee scheme for subscriber and service according to the requirements of the subscriber, service and system. This scheme uses two kinds of the classification table, which are called 'service classification table' and 'subscriber classification table.' Using the classification table, we can identify the flow of the subscriber and service. Also, we compute the number of hash table entry to minimize the loss ratio of flows using the M/G/k/k queueing model. Finally, we apply the DRR scheduling through virtual queueing per subscriber instead of the aggregated class.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1201-1209
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• 2009

Recently, the convergence of the telecommunications industry through the development of network media has brought along interactive data services in addition to the traditional broadcast services by providing direct connections between the users and the broadcasters. This can be easily achieved by the combination of existing network technology and multimedia technology, but in reality, as seen in the actual implementation of IPVT, it's difficult to provide satisfactory levels of service to users due to issues of network bandwidth and problems of streaming system. In particular, a network which is able to fully support Qos/QoE, and also a fast enough channel changing technology that is satisfactory to the user, are prerequisites for IPTV success. Therefore this thesis proposes a fast channel changing technique to delivery enhanced IPTV user experience. Recent IP set-top-boxes use only a small portion of the CPU to feed Ethernet packets to the hardware decoder and play them. Thus, by making IP set-top-boxes share cached channel information and content with each other, reducing the load on the server and enhancing the channel changing time is made possible.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.93-106
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• 2011

In this paper we describe an efficient and easy to use internet stopper, which is called AINS (Automatic Internet Stopper), which uses ARP spoofing scheme. Instead of forwarding packets to router for the case of hacking, in ARP spoofing, the AINS ignores all the packets so that internet stopping operates. The AINS program needs to be installed only in manager computer that does not require additional agent program. In addition to setting manually the stopping computer list, it is able to indentify network nodes automatically by analyzing broadcasting packets. The experimental results show that less than 4 secs for spoofing interval is enough for blocking internet usage regardless the number of computers and therefore network overhead is negligible. The AINS can indentify and control network nodes not only on same subnet but also on different subnet only if they are connected onto same ethernet switch physically. It is being used for an efficient tool for controling internet usage of university computer laboratory and also for an efficient network management.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.11
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• pp.73-82
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• 2011

As a demand of IP based packet service is increasing, transport network is evolving from circuit based transport technology using TDM to Ethernet based packet transport technology. In this paper we introduce packet transport network based on PBB-TE and MPLS-TP and propose a quality of service(QoS) management scheme to satisfy various user requirements in packet transport network. The proposed flow-based QoS management scheme guarantees that per-flow bandwidth control satisfies the predefined QoS requirement perfectly under bandwidth congestion condition by using perflow and per-PTL tunnel management. In order to evaluate the proposed scheme we defined flow and PTL tunnel per input frame and configured QoS parameters for each flow and PTL tunnel respectively. Simulation was done by using OPNET modeler 16.0 version.