http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
An Efficient Transaction Cancellation Mechanism of Session Initiation Protocol
Jaecheon Han,Shingak Kang 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7
SIP is a transactional protocol. There are two types of transactions depending on the method of the request: INVITE transaction and NON-INVITE transaction. RFC3261 describes state machines for SIP transactions. Unfortunately, there is a hole in the one of the state machines. When UAC cancels INVITE transaction, a race condition might be occurred. In that case, UAC believes the session is cancelled, but UAS believes the session is immediately established. In this paper, we will describe that why the problem break out and how the problem can be overcome.
한재천(JaeCheon Han),강신각(SinGak Kang) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅲ
VoIP(Voice over IP) 기술들 중에서 IETF(Internet Engineering Task Force)에서 제안한 텍스트 기반의 SIP(Session Initiation Protocol) 프로토콜은 다양한 애플리케이션을 개발할 수 있는 등의 장점을 가지고 있기 때문에 차세대 네트워크에서 호 설정을 위한 사실상의 표준으로 자리 잡아가고 있다. SIP는 계층적 구조를 갖는 프로토콜로서, SIP의 일부 계층은 대부분의 SIP 응용 애플리케이션에서 공통적으로 사용될 수 있다. 본 논문에서는 SIP 애플리케이션 개발에 효과적으로 사용될 수 있도록 설계 및 구현된 SIP 공통모듈에 대하여 설명한다.
Jaecheon Sohn,S. H. Han,Masahiro Yamaguchi,S. H. Lim 한국자기학회 2007 Journal of Magnetics Vol.12 No.1
Si-based electromagnetic noise suppressors on coplanar waveguide transmission lines incorporated with a SiO₂ dielectric layer and a nanogranular Co-Fe-Al-O magnetic thin film are reported. Unlike glass-based devices, large signal attenuation is observed even in the bare structure without coating the magnetic thin film. Much larger signal attenuation is achieved in fully integrated devices. The transmission scattering parameter (S21) is as small as ?90 ㏈ at 20 ㎓ at the following device dimensions; the thicknesses of the SiO₂ and Co-Fe-Al-O thin films are 0.1 μm and 1 ㎛, respectively, the length of the transmission line is 15 mm, and the width of the magnetic thin film is 2000 ㎛. In all cases, the reflection scattering parameter (S₁₁) is below -10 ㏈ over the whole frequency band. Additional distributed capacitance formed by the Cu transmission line/SiO₂/Si substrate is responsible for these characteristics. It is considered that the present noise suppressors based on the Si substrate are a first important step to the realization of MMIC noise suppressors.
조재천(Jaecheon Jo),문남수(Namsu Mun),이기주(Kiju Lee),한인수(Insu Han),김종일(Jongil Kim),김희진(Heejin Kim) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5
Failure of the exhaust pipe can cause air pollution by reducing ability of exhaust gas purification and can cause noise pollution and ride degradation by reducing ability of noise isolation. Therefore, it should ensure high reliability of the product to meet the growing environmental regulations and the needs of consumers. However, under actual conditions of use, it spends a lot of time and cost in order to develop products of high reliability. Therefore, accelerated life test to estimate the relationship between stress and life is performed to predict the actual life from the observed data through tests of the product by promoting the failure of products in severe conditions than real use conditions. The purpose of this study is estimating lifetime of exhaust pipes through accelerated life test and to evaluate average life, failure rate and etc. in short term.