• Korean journal of applied entomology
• /
• v.40 no.2
• /
• pp.125-129
• /
• 2001

Some wingless species have evolved take-off behaviors that enable them to become airborne. We examined aerodynamic attributes of dispersal relative to the body size and standing vs. walking postures for three phytoseiids that were suspected to have different take-off behaviors and dispersal abilities, Phytoseiulus persimilis Athias-Henriot, Neoseiulus fallacis (Carman) and N. californicus (McGregor). The average vertical profile of Pp in the walking position was significantly higher than those of Nf and Nc when in walking position. The body height of Nf in the standing posture was significantly greater than the body height of Pp when in the walking position. Cross-section areas also showed similar patterns of difference. Nf in the standing posture would have more than twice the drag force than in walking posture because of more fluid momentum in the wind boundary layer However, Pp in the walking position would have similar drag to Nf in the standing posture because of a higher vertical profile and larger size. Thus we add the scientific evidence of presence and absence of take-off behavior of some phytoseiid mites and evolutionary aspects of aerial dispersal are further discussed.

• The Magazine of the IEIE
• /
• v.22 no.6
• /
• pp.71-82
• /
• 1995

공중통신망에서 광대역 통신 서비스의 제공을 위해서는 가입자망의 광대역화가 필수적이다. 그러나, 가입자망의 광대역화에는 막대한 양의 투자가 필요하기 때문에 체계적이고 경제적인 지화계획의 수립이 요구된다. 본 고에서는 현재 세계 각국에서 중점적으로 연구되고 있는 광대역 가입자망의 구성 기술에 대하여 살펴 보고, 이에 대한 국제적인 표준화 현황, 그리고 한국의 가입자망 상황과 바람직한 진화 방안에 대하여 검토하여 보겠다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.3
• /
• pp.451-461
• /
• 1994

For developing countries which are in infant state of data communication services or don`t have their own Packet Switched Public Data Network(PSPDN), we present the strategy to construct the public data communication network, which guarantees the easy diffusion of data communication services, agrees with trends of telecommunication technology, and maximizes the outcomes to investments. With analyzing the characteristics of telecommunication infrastructures and demands of data communication services in a developing country, we show that the introduction of ISDN is the best solution for constructing a public data network. We also suggest aggressive approach to realize the packet switching functions into ISDN switching system and the networking scenario consisting of three graceful steps, based on the evolution of network architectures. Finally we show that the TDX-10 ISDN switching system, which is designed especially for developing countries, is helpful to commence the data communication era.

• Information and Communications Magazine
• /
• v.7 no.2
• /
• pp.77-89
• /
• 1990

컴퓨터와 통신 기술의 결합으로 기존의 공중전기통신망(PSIN) 과 비음성 서비스를 동시에 제공해 줄 수 있는 종합정보통신망(ISDN)으로 진화되고 있다. CCITT에서는 ISDN의 기본신호방식으로 No.7 신호방식을 권고하고 있으며, 국내에서도 이미 2000년대 통신망의 기본 신호방식으로 No.7 신호방식을 채택하기로 확정하였다. No.7 신호방식에 따른 공통선 신호망이 구성되면 기존의 통신망은 ISDN으로의 진화가 가능하게 되고, 다양하고 부가가치가 높은 새로운 서비스를 제공함으로써 지능망으로 확장이 가능하게 된다. 또한 공통선 신호망의 구성은 각종 뉴미디어의 출현으로 구성되는 부가가치 통신망간의 정보 교환을 가능하게 한다. 본고에서는 공통선신호망 구성계획을 보다 효과적으로 수립할 수 있도록 지원하기 위하여 KAIST와 ETRI에서 공통으로 개발된 신호망 설계지원시스템(SINEPS)을 소개한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.10b
• /
• pp.1275-1278
• /
• 2001

최근 공중통신망은 다양한 서비스 요구사항의 변화와 ATM, MPLS 및 DWDM 등의 새로운 전달망 기술의 발달과 같은 통신 파라다임의 변화로 인하여 개방형 구조의 초고속 통합 패킷 통신망 구조를 갖는 차세대 통신망으로 진화하고 있다. 그러나 차세대 통신망에서도 기존의 음성서비스는 통신사업자 관점에서 중요 서비스로 계속적인 기술 개발이 연구되고 있다. 본 논문에서는 차세대 통신망에 적용하여 기존의 음성서비스뿐만 아니라 다양한 신규 서비스들을 수용할 수 있는 media gateway에서 효율적인 대역관리 방법을 제안한다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 1998.10a
• /
• pp.179-184
• /
• 1998

기존의 공중전기 통신망들이 B-ISDN으로 통합, 발전되어 가는 과정에서 경제성 및 효율성 등의 이유로 인해 필연적으로 기존망과 연동과정이 필요하게 되며, 이러한 B-ISDN 통신망의 연동계획은 가능한 최적의 통신망 진화전략에 부합되어야 하고, 다양한 기술의 응용 가능성을 제한하지 않도록 수립되어야 하며, 또한 기존망의 기능을 수용하면서 구현될 수 있는 방안이 마련되어야 한다. 따라서 본 논문에서는 B-ISDN과 N-ISDN의 망간 연동 프로토콜을 설계하고 설계한 프로토콜을 워크스테이션 상에서 구현하였으며, 구현한 프로토콜이 표준 규격과 일치하게 동작하는지 테스트하기 위하여 적합성 테스트 중 오류 검출 능력이 우수한 국부시험 방법을 이용하여 구현된 프로토콜이 정상적으로 동작함을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.7
• /
• pp.1272-1279
• /
• 2001

Owing to the change of various services requirement and the change of communication paradime as the development of new transit network technology: ATM, MPLS and DWDM, the latest PSTN is evolving into the next generation network, which have the very high speed integrated packet network of open-type structure. but in the next generation network, the existing voice service is being researched for the continuous technology development as the important service from the viewpoint of communication business. This paper suggests the method of efficient bandwidth management in the media gateway that can accommodate the various new services as well as the existing voice services by appling to the next generation network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.709-712
• /
• 2004

The BcN is applying from public networks to local networks and each terminal step by step under supporting MIC(Ministry of Information and Communication Repoblic of Korea) until 2007. The architecture of network sorority should considers BcN environment and evolves to manage Ipv6 traffics. The next generation network security architecture can manage not only Ipv6 environment but also wire and wireless integrated network. We suggest the next generation network security architecture for Ipv6 environment and wire-wireless integrated network environment and verify the performance of the suggested architecture using network security scenario.

• The Journal of the Korea Contents Association
• /
• v.20 no.6
• /
• pp.460-469
• /
• 2020

This study analyzes online news articles and cafe articles on the '5-day Rotation Mask Distribution System', which is emerging as a recent issue due to the COVID-19 incident, to identify the mass media and social media agendas containing media and public reactions. This study figured out the difference between mass media and social media. For analysis, we collected 2,096 full text articles from Naver and 1,840 posts from Naver Cafe, and conducted word frequency analysis, word cloud, and LDA topic modeling analysis through data preprocessing and refinement. As a result of analysis, social media showed real-life topics such as 'family members' purchase', 'the postponement of school opening', ' mask usage', and 'mask purchase', reflecting the characteristics of personal media. Social media was found to play a role of exchanging personal opinions, emotions, and information rather than delivering information. With the application of the research method applied to this study, social issues can be publicized through various media analysis and used as a reference in the process of establishing a policy agenda that evolves into a government agenda.

• Journal of Internet Computing and Services
• /
• v.10 no.6
• /
• pp.27-36
• /
• 2009

PSTN (public switched telephone network) provides voice communication service, whereas IP network provides data oriented service, and we can use IP network for multimedia transport service (e.g. voice over IP service) with economic price. In this paper, we propose RoIP (robot on IP) service scenario, signaling call flow, and implementation to provide home automation and monitoring service for remote site users. In our scheme, we used a extended SIP (session initiation protocol) for signaling protocol between remote site users and home robots. For our bearer transport control, we implemented H.263 video codec over RTP (real-time transport protocol) and additionally DTMF (dual tone multi-frequency) transport for robot actuator control. We implemented our scheme on home robots and experimented with KTF operator network, and it shows good communication quality (average MOS = 9.15) and flexible robot controls.