• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.138-141
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• 2009

모바일 명함 관리 시스템은 간편하게 모바일 기기를 이용하여 명함을 등록하고 검색할 수 있으나 모바일 기기의 특징상 화면이 작고 정보를 이용하기 위해서는 펜을 이용하여 검색어를 입력해야하는 불편함이 있다. 이를 해결하기 위해 명령을 음성으로 처리하고자하는 VUI(Voice User Interface)의 필요성이 증가하였다. 또한 모바일 기기의 메모리 공간상의 제약으로 인한 음성인식엔진 탑재의 어려움이 있다. 이에 본 논문에서는 모바일 단말기로부터 음성을 입력받아 인식결과를 모바일 단말기로 되돌려 주는 음성인식 시스템을 구축하고 본 인식시스템과 모바일 클라이언트 시스템을 분산처리 가능한 웹서비스 환경으로 구성하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.996-998
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• 2011

인터넷의 발전과 더불어 네트워크 상에서의 침입 시도가 갈수록 증가되고 다변화되고 있으며, 특히, 네트워크나 서버의 가용성을 위협하는 형태의 서비스 거부(DoS: Denial of Servie) 공격이 최근 급증하고 있다. 따라서, 본 논문에서는 인터넷 서버의 정상적인 서비스 제공을 방해하는 형태의 분산 서비스 거부(DDoS: Distributed Denial of Service) 공격으로부터 서버를 보호하고 원활한 서비스를 제공하기 위한 Secure-NIC 시스템의 설계 및 구현에 대해서 설명한다. 이는 "CISGDP : CPU-Independent Service Guaranteed DDoS Protection" 이라는 설계 개념하에서, 각종 인터넷 서버에 장착되어 DDoS 공격 등의 네트워크 공격에 대하여 서버의 고유 서비스가 지속적으로 보장될 수 있도록 자체 보안 기능을 NIC(Network Interface Card) 형태로 제공한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.69-72
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• 2003

This paper presents a signal processing IC for digital HDTV, which is designed to operate in bunt-in HDW or in HD-set-top Box. The chip supports de-multiplexing an ISO/IEC 13818-1 MPEG-2 TS stream. It decodes MPEG-2 MP@HL video bitstream, and provides high-quality scaled video for display on HDTV monitor. The chip consists of ARM7TDMI for TS-Demux, PCI interface, Audio interface, MPEG2 MP@HL video decoder Display processor, Graphic processor, Memory controller, Audio int3face, Smart Card interface and UART. It is fabricated using Sam sung's 0.18-um and the package of 492-pin BGA is used.

• The Transactions of the Korea Information Processing Society
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• v.4 no.10
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• pp.2521-2532
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• 1997

The next generation internet protocol, IPv6, have been developed by the IETF according to the requirements of enhancement of classic IP protocols to satisfy the lack of Internet address space as well as the support of multimedia applications. This paper presents an implementation of IPv6 protocols on the Windows NT kernel environment. In this work, we developed and also tested the basic functions, required for operating as an IPv6 host, such as IPv6 header processing, IPv6 address handling, control message processing, group membership processing and neighbor discovery functions. The implemented IPv6 protocol driver module is connected to the lower network interface card through NDIS, a standard network interface. And this driver module that operates within kernel, is implemented as it is connected to upper user applications and lower NDIS using dispatch and lower-edge functions. The developed IPv6 protocol driver can provide not only enhanced performance because it is implemented in kernel mode, but also convenience of usage to the application developers because it gives user interface as a dynamic link library.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.23-28
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• 2005

Recently, new concept, NP(Network Processor) was emerged into communication systems to cope with the various service requirements from Internet users. NP is an unique promising technique to capable of implementing of the packet processing in wire-speed and providing the flexibility for supporting the newly network services, having satisfied with implementation using hardware and software respectively in past, This paper deals with the implementation techniques and evaluation results of the line card capable to do packet forwarding function with packet processing power of wire-speed and applicable to various physical interfaces. There are several interfaces of POS, Gigabit ethernet and EPON in E-OLT(EPON Optical Line Terminal) system of PATH(Photonic Access To Home) network. Therefore, the E-OLT's packet forwarding engine have to support various subscriber's interface in wire speed. Our system is implemented the subscriber's card in daughter board and the setup procedure is done by system firmware based on the module's identifier acquired from installed physical board.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.79-87
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• 2010

This paper proposes a L3 handover method to minimize packet loss for supporting service continuity to IMS Terminal which has a single WLAN interface. The existing IMS based handover solution is able to support handover between different access networks in case that a terminal has multiple interfaces. That is, WLAN terminals need multiple interfaces to connect with one or more access networks. This proposed method configures IP address for the terminal in target WLAN previously by using Candidate Access Router Discovery(CARD) mechanism. Also, in the proposed method, service continuity server performs L3 connection establishment in target WLAN and registration to IMS server instead of the terminal. And then session control mechanism based on SIP is performed to support service continuity. We analyzed handover latency and signaling cost in the proposed method and existing method to show the improved performance by the proposed method.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.55-61
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• 2019

In order to realize foreign language education, various existing educational media have been provided, but there are disadvantages in that the cost of the parish and the media program is high and the real-time responsiveness is poor. In this paper, we propose an artificial intelligence English conversation system based on VR and speech recognition. We used Google CardBoard VR and Google Speech API to build the system and developed artificial intelligence algorithms for providing virtual reality environment and talking. In the proposed speech recognition server system, the sentences spoken by the user can be divided into word units and compared with the data words stored in the database to provide the highest probability. Users can communicate with and respond to people in virtual reality. The function provided by the conversation is independent of the contextual conversations and themes, and the conversations with the AI assistant are implemented in real time so that the user system can be checked in real time. It is expected to contribute to the expansion of virtual education contents service related to the Fourth Industrial Revolution through the system combining the virtual reality and the voice recognition function proposed in this paper.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.400-404
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• 1999

The conventional mercury delay method to measure compressional wave velocity of unconsolidated sediment is inconvenient because the signal must be analyzed on the oscilloscope and the mercury column has to be calibrated between measurements. We developed an automated compressional wave velocity measurement technique by connecting an oscilloscope and a PC with a GPIB (General Purpose Interface Bus) card. The GPIB card buses signals from the oscilloscope to the PC where the signal from a sample is analyzed and compared to the input pulse thereby the compressional wave velocity of the sample is computed and recorded automatically. Differences between the mercury delay method and the automated measurement technique are negligible except the slightly greater velocity in the automated measurement technique. We concluded that the new technique can be used to measure the velocity for unconsolidated marine sediment. It also has an advantage to calculate sediment attenuation through the processing of waveform using the spectral ratio technique.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.37-43
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• 2002

This paper describes the performance evaluation and analysis of Wireless Local Area Network (W-LAN) in the 5 GHz ISM-band in compliance with IEEE 802.11a. At present, most W-LAN products are based on 2.4 GHz band, but low speed (11Mbps) has the limitation to serve systems demanding high-speed data transmission. To solve this problem, it is necessary to design next generation W-LAN system with 54Mbps in the 5GHz. It is sure that implementation of next generation W-LAN will bring competitive advantages. In particular, it will support telecommunications for high-speed mobile environments as well as for fixed places such as a school zone, a lecture room, a hospital and other premises. A few simulation methods are applied to more accurate and reliable performance analysis of next generation W-LAN. To verify if continuous data service is supported for a high-speed mobile notebook, multi-path fading channels between wireless Access Point (AP) and wireless Network Interface Card (NIC) are modeled. In addition, low interference is analyzed via convolutional codes and Orthogonal Frequency-Division Multiplexing (OFDM). Also, to obtain reliable Bit Error Rate (BER), a single tap Least Mean Square (LMS) equalizer is applied. Given the above simulation, next generation W-LAN is an ideal solution for continuous data transmission in high-speed mobile environments.