• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.104-110
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• 2007

FTTH상용화, IEEE802.11n 무선랜 기술의 상용화 등과 같은 초고속 전송기술의 발전에 따라 홈네트워킹 환경 또한 급격하게 변화하고 있다. 100Mbps를 초과하는 많은 홈네트워킹 기술들의 개발로 인해 홈게이트웨이에 보다 넓은 대역의 LAN 인터페이스를 요구하게 되었고, xDSL이나 케이블모뎀 기반의 가입자망과의 대역폭 차이는 고성능의 QoS 기능을 요구하게 되었다. 이러한 통신환경을 토대로 홈게이트웨이의 기능에 대한 요구사항을 분석하고 홈게이트웨이용 스위칭 칩의 개발규격을 도출하였다. 그리고 새로운 네트워크 기반의 비즈니스 모델을 개발하고자 하는 통신사업자의 요구사항과 QoS나 IPv6등의 다양한 네트워크 요구사항을 등을 유연하게 수용할 수 있으며, 칩의 기능과 성능을 수정하 또는 추가할 수 있는 네트워크 프로세서 기반의 기가빗 스위치 칩을 개발하였다. 개발 칩은 패킷 프로세서로 Layer 4까지 의 패킷헤드를 처리하고, 2기가빗이더넷 + 6패스트이더넷 포트를 갖도록 설계하였으며, FPGA를 이용하여 스위칭 칩의 기본적인 전송기능과 성능, Flow별 패킷 분류 및 패킷 필터링, 스케쥴링 기능 등의 시험을 통하여 설계한 칩의 기능과 성능을 확인하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.473-476
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• 2007

최근 방송 통신 기술의 눈부신 발전에 힘입어 등장한 데이터 방송(Data Broadcasting)은 시청자에게 영상과 음성환 아니라 기존에는 접할 수 없었던 다양한 서비스들을 제공하고 있다. 이런 데이터 방송을 수신하기 위해서는 TS로부터 데이터를 추출하고 처리할 수 있는 미들웨어(middleware)가 포함된 셋탑박스(set-top box)가 필요하다. 그리하여 MHP, OCAP, ACAP 등 여러 데이터 방송 시스템의 미들웨어 표준 규격이 정의되었다. 그 중 MHP의 경우, OpenMHP라는 오픈 소스 프로젝트를 통해 PC 상에서 간단하게나마 MHP API를 테스트 해 볼 수 있는 환경을 제공해 주고 있다.[1] 하지만 셋탑박스 내에서 하드웨어를 이용하는 작업들은 거의 구현되지 못 했기 때문에 테스트에 있어 극히 제한적일 수밖에 없었다. 따라서 본 논문에서는 소프트웨어적으로 셋탑박스 환경을 에뮬레이션 해주는 Virtual Set-Top Box(VSTB)를 설계, 구현하였다. 셋탑박스가 없는 환경이나 간단한 시뮬레이션이 필요한 경우, 실시간 스트림 역다중화와, 파싱, 필터링 작업등이 지원되는 가상 셋탑박스 시스템을 통해 MHP 미들웨어 API를 테스트하는데 유용한 역할을 할 수 있을 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.528-532
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• 2005

As the current IEEE 802.11 wireless LAN standard provides the unified channel access procedure for each traffic service without considering its own traffic characteristics, it is difficult to get its differentiated service qualities at IEEE 802.11 wireless LAN system. To solve this limit, IEEE 802.11e standard that can provide differentiated service to each traffic is under preparation. In this study, we implemented IEEE 802.11e EDCA channel access scheme with NS-2 simulator, and showed its numerical results in various system environments with using average delay and throughput as performance measures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.445-452
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• 2010

In this paper, an attempt has been made to design the controller applicable for H.264 level3 encoder of baseline profile on full hardware basis. The designed controller module first stores the images supplied from CMOS Image Sensor(CIS) at main memory, and then reads or stores the image data in macroblock unit according to encoder operation. The timing cycle of the DMA controller required to process a macroblock is 478 cycles. In order to verify the our design, reference-C encoder, which is compatible to JM 9.4, is developed and the designed controller is verified by using the test vector generated from the reference C code. The number of cycle in the designed DMA controller is reduced by 40% compared with the cycle of using Xilinx MIG.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.355-359
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• 2008

와이브로(WiBro), 3G 무선인터넷(HSDPA), 3G LTE 등과 같은 와이어리스 브로드밴드(Wireless Broand) 기술이 점차 성숙됨에 따라 이들 망을 활용한 다양한 무선인터넷 서비스를 제공하려는 사업자들이 증가하고 있다. 기존의 WLAN, 2G/3G 회선망에서의 제한된 이동성 및 네트워크 전송 속도를 개선한 와이어리스 브로드밴드 서비스 시장은 국내에서도 2006년부터 WiBro 및 HSDPA가 사용됨에 따라 사업자간의 경쟁도 본격화되고 있다. 이러한 환경 속에서 사업자들은 신속하고 편리한 서비스 개통과 스마트폰, USB모뎀, 노트북, UMPC, PMP등 다양한 단말들의 펌웨어 업그레이드, A/S 처리 방안에 대해 고심을 하고 있으며, 이들 문제점은 막대한 비용과 고객 민원을 야기시키는 요인이기도 하다. 따라서 경제적인 관리비용으로 동적인 서비스/펌웨어 업그레이드 및 A/S에 대한 고객 만족도를 높이기 위한 단말 원격 관리 필요성이 절실히 요구된다. WiBro 단말의 안전하고 효율적으로 관리하기 위해서는 단말과 기지국사이의 무선구간에 대한 보안(security)을 강화시켜 줄 수 있으면서 이동성(mobility)을 고려한 OMA DM프로토콜을 이용하는 것이 적합하다. 또한, WiBro에서 가입자 인증을 채택하고 있는 UICC의 관리를 위해서 3GPP에서 정의하는 SMS/MMS기반의 또는 BIP(Bear Independent Protocol)기반의 OTA기술을 병행하여 사용하여야 한다. 본 논문에서는 Wi-MAX단말 관리를 위한 OTA Provisioning 규격으로 OMA DM과 TR069이 WiMAX 단말을 위하여 어떻게 적용하도록 규정하고 있는지를 살펴본다. 특히, WiBro 가입자 인증뿐만 아니라 폰북, DRM, 금융서비스 등 다양한 부가 서비스를 위하여 사용되는 UICC의 원격관리를 위한 관리 요소들을 정의, 설계하고 이를 바탕으로 구현된 KTUICC OTA Provisioning시스템을 소개한다.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.21-26
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• 2024

Urban air mobility (UAM) is being considered as an alternative to transportation in urban areas where traffic congestion is increasing. It is judged that it will be difficult to manage the complex UAM operation environment with the existing Air Traffic Service, which is a person-centered service. Therefore, an advanced information processing-based traffic management system for UAM (UATM) is needed. Airspace management is essential to establish a systematic UAM traffic management (UATM) environment. In particular, the establishment of exclusive corridors where UAM aircraft can operate safely can provide opportunities to operate UAM aircraft without violating the minimum flight altitude regulations. This study conducted an empirical analysis using a helicopter of similar size to UAM to establish the cross-track dimension of the corridor for UAM operation. The research results can be used as a guideline when designing UAM corridors.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.17-23
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• 2020

In this paper, collecting real-time data frames that occur during RS232 communication between an HMI and PLC of automation equipment by sniffing real-time information data frames through MCU without modification of the HMI or PLC, a method is proposed that allows users to collect data without being dependent on the modification of PLC and HMI systems. The user collects necessary information from the sniffing data through the parsing operation, and the original communication interface is maintained by transmitting the corresponding sniffing frame to the destination. The MCU's UART communication interface circuit is physically designed according to the RS232 communication standard, and this additionally improves efficiency more so than an interrupt-based system by using the DMA device inside the MCU. In addition, the data frame IO operation is performed by logically separating the work of the DMA interrupt service routine from the work of the main thread using the circular queue. Through this method, the user receives the sniffing data frame between the HMI and PLC in RS232 format, and the frame transfer between PLC and HMI arrives normally at the original destination. By sniffing the data frame without further modification of the PLC and HMI, it can be confirmed that it arrives at the user system normally.

• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.975-983
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• 1998

In these days, information communication systems are based on both open distributed computing technologies and object-oriented techniques like inheritance, encapsulation and object reuse to support various system configuration and application. As information systems are interconnected through unsecure networks, the need for the secure information exchange is more critical than before. In this paper, we have designed and implemented a transparent CORBA-basce Security infrastructure with authentication, security context association, access control and security information management to support a secure applications in distributed object environment. SESAME Ver. 4 was adopted as an external security service to manage user privilege attributes and to distribute keys for data encryption, decryption and integrity. Using filter and transformer with an interface to Object Request Broker, it provides a transparent security service to applications. The filter objects are special classes that allow additional parameters to be inserted into messages before they are sent and removed just after they are received. The transformer objects are special classes that allow direct access to the byte stream of every messages for encryption and decryption before it is sent and just after it is received. This study is to implement the access control interceptor(ACI) and the secure invocation interceptor(SII) of secure ORB defined in CORBA using filter and transformer.

• Journal of KIISE
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• v.44 no.3
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• pp.332-337
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• 2017

When using IFC data consisting of STEP schema based on the EXPRESS language, it is not easy for collaborating project stakeholders to share BIM modeling shape information. The IFC viewer application must be installed on the desktop PC to review the BIM modeling shape information defined within the IFC, because the IFC viewer application not only parse STEP structure information model but also process the 3D feature construction for a 3D visualization. Therefore, we propose a lightweight data structure design for web visualization by parsing IFC data and constructing 3D modeling data. Our experimental results show the weight reduction of IFC data is about 40% of original file size and the web visualization is able to see the same quality with all web browsers which support WebGL on PCs and smartphones. If applied research is conducted about the web visualization based on IFC data of the last construction phase, it could be utilized in various fields ranging from the facility maintenance to indoor location-based services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.267-270
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• 2016

Currently, tire has a variety of information to know the information of the tire are displayed on the tire side. the market are marked with raised letters showing a variety of information relating to the tires. Such information enables people and tire related companies to distinguish between tires upon the information marked on the tires. Generally, people see the information including max press, manufacturing date, etc. Accordingly, studies on automated recognition of raised letters on tire by using image processing technology have been presented consistently. However, they lack a method for recognition of letters and improvement of the recognition. Moreover, the raised letters have been previously recognized through image processing. Further, to obtain the character recognition of a conventional side in video, it is suitably utilized the effects of lighting time of acquisition, so as part of the background and the character has a gray level values between approximately the same, is the part that is not relatively clear are many scattered. In this paper, we see the characters of the tire side using the laser sensor, recognition, was designed for character recognition of the tire side.