효율적이며 신뢰성 있는 그룹통신 프로토콜의 설계에 관한 연구

이광휘 國立 昌原大學校 基礎科學硏究所 1993 基礎科學硏究所論文集 Vol.5 No.-

Reliable and efficient communication among the numbers of a group, referred to as reliable multicast or group communication, is one of frequently-issued problems to solve in designing fault tolerant distributed systems In this paper, we designed the group communication protocol which is low protocol-message overhead and efficient. The atomic and reliable group communication protocol designed in this paper guarantees that each message sent to a group is delivered to all surviving processes in the group or none of them. We have introduced the concept of multi-domain group for supporting multi-group communication.

C++를 이용한 통신 시뮬레이터의 설계 및 구현

이광휘,정상국,안정희,김한경,이종근 國立 昌原大學校 精報通信硏究所 1998 精報通信論文集 Vol.2 No.-

In this paper, we are designed and implemented communication simulator, for two systems which communicates in peer-to-peer and simulating for protocol, to verify the interwork not yet designed system Peerl and now being operated Peer2. To begin with, after the investigation in Interworking Standard in Interface Control Document and check the satisfied requirements in each system, the environment of simulator is set up. We examine Interworking Standard in FSM representation. And in protocol design, partial steps follows necessary procedure of protocol engineering. Simulator is implemented in C++ and, to interwork two systems smoothly, the whole system will be merged. Finally, a design and implementation of simulator is completed by confirming simulation results of simulator and Interworking Standard coincide.

동적 그룹 지원을 위한 계층적 그룹통신 프로토콜

이광휘,조현주,김한수 昌原大學校 基礎科學硏究所 1995 基礎科學硏究所論文集 Vol.7 No.-

This paper presents a hierarchical group communication based on multicast protocol, HGCMP. Group communication facility has been gradually magnified. As an object oriented approach has been introduced in designing the system, it provides an application programmer with the means to develop a new application facility without having to build the detail functions. In this paper, some requirements for multicast communication, the structure of the system, and service primitives will be described in detail. As the number of manager can be dynamically created and destroyed relying on the requirement, the system can efficiently be operated. Also the use of hierarchical structure has a advantage. Appropriate management functions can be allocalted to each management level. The manager in the highest domain totally performs configuration, fault, name service and perfomance management functions. The lower managers perform these management functions on the managed objects in the corresponding level host machine. Multicast facility designed in this paper is for supporting a distributed network management system.

Configuration 관리 시스템의 설계에 관한 연구

이광휘 國立昌原大學校 基礎科學硏究所 1992 基礎科學硏究所論文集 Vol.3 No.-

In this paper, the structure of configuration management system is designed and validated. For this, some protocols are defined and constructed. The implementation environment is provided to implement this configuration manager. The configuration manager supports various configuration management services through communication primitives. One of the important factors of this system is the simulator which supports an appropriate configuration. The configuration domain concept is introduced in order to manage logical and physical networks. Through this study, it was possible to construct a configuration management system for the networks which have different characteristics.

통합 통신망 관리 시스템 구축 방안 연구

이종근,임미경,이광휘,김한경,김태수 國立 昌原大學校 精報通信硏究所 1998 精報通信論文集 Vol.2 No.-

This paper presents a system for internetworking between different network management protocols. The internetworking system between SNMP(Simple Network Management Protocol) and CMIP(Common Management Information Protocol) has been designed. SNMP has been used as a standard protocol in Internet while CMIP has been selected as management protocol in OSI network. This approach is different from previous researches which convert protocols between management protocols. We have newly defined manage objects structure. Thus, even if a new management protocol would be introduce in addition, the new gateway system needs not be designed. We can achieve it through minimum modification in the interface of the managed objects. So, we can support managed objects defined previously using MOVI(Manage Object View Interface) concept presented in our previous research. Through this research, we have some additional benefits: it is able to internetwork between more complicated network management protocols, to increase usefulness of SNMP and CMIP, also it will use in internetworking between new network management protocols.

실리콘 웨이퍼 공정용 알루미나 정전척의 제작과 특성에 관한 연구

천희곤,조동율,이영섭,박용균,최성호,정광진,Serguei Spoutai 울산대학교 기계부품 및 소재 특성평가연구센터 1999 연구보고서 Vol.1999 No.-

정전척의 유전체 물질로 열전도도와 유전특성 그리고 기계적 특성이 우수한 알루미나에 TiO₂첨가하여 유전체의 비저항을 변화시켜서 정전척(electrostatic chuck)에서 발생하는 정전력인 쿨롱힘(coulomb force)과 존슨-라벡힘(Johnsen-Fahbeck firce_의 영향을 규명하려 하였다. 그리고 비저항, 인가전압, 온도, 습도가 정전력에 어떠한 영향을 주는지 고찰하였으며, 인가전압에 따른 응답 특성에 관하여 고찰하였다. Alumina electrostatic chucks for silicon wafer process with wide range of electrical resistivity were fabricated by controlling the amount of TiO₂ addition (0 wt%, 1.3 wt%, 2 wt%, 2.8 wt%). The dependence of electrostatic force on applied voltage, temperature and humidity was investigated. In addition, response characteristics on applied voltage and relationship between electrical resistivity and electrostatic force characteristics such as Coulomb force and Johnsen-Rahbeck force were discussed

네트워크 시뮬레이터를 이용한 확장 QoS 제공 라우팅 프로토콜의 설계 및 구현

김현주,이광휘 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

Recently, various multimedia applications including a lot of QoS requirements have been emerging. However, the existing routing protocols are insufficient and inadequate to calculate the path that satisfies these QoS constraints. Therefore, this study has proposed a QoS routing protocol that can select an appropriate path satisfying the QoS requirements of some multimedia applications. The proposed protocol and methods have been implemented on a network simulation tool called NetDAS. It has the functionality to predict the possible problems and performance of network devices and links in QoS-aware environment. For this approach of QoS support routing protocol, existing OSPF has been modified and expanded. Bandwidth and delay metrics that are the representative QoS requirements have been considered to calculate the cost for path selection. The NetDAS has been used to analyze the performance of proposed protocol. Simulation and results have shown that the proposed routing protocol decreases the number of QoS request packet drop and lowers delay variation in comparison with existing OSPF. Also these have proved that transmission of QoS request packet by proposed routing protocol is well accomplished an stable than existing OSPF.

분산 네트워크 관리 시스템 지원을 위한 멀티캐스트 프로토콜의 설계 및 구현

조현주,이광휘,김한수 國立昌原大學校 基礎科學硏究所 1994 基礎科學硏究所論文集 Vol.6 No.-

This paper presents a new model for group communication facility which is gradually magnified. This model has been implemented in LAN environment and can get the enhancement in performance because a new manager can be dynamically created determined depending on the type of receiving message. As an object oriented approach has been introduced in designing the system, it provides an application programmer with the means to develop a new application facility without having to build the detail functions. As the members in a group are only identified by the index in a table, the overhead for the address referencing can be minimized. In this paper, some requirements for multicast communication, the structure of the system, and service primitives will be describe in detail. As the number of manager can be dynamically created and destroyed relying on the requirement, the system can efficeintly operated. Multicast facility designed in this paper is for supporting a distributed network management system.

DiffServ 환경에서 Mobile Xcast 지원에 관한 연구

배진호,김태수,이광휘 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

In the third generation of mobile computing environment, the applications that are compatible with small members of group in which the applications join the multicast sessions such as Internet phone, video conference and networked games are more prevalent. However, since the traditional multicast mechanisms supporting the mobile computing are suitable for large members of group in the multicast session, we need to consider a new mechanism to complement them. Therefore, in this paper we suggest a new multicast model that adopted explicit multicast(xcast), which has more gradual deployment with legacy Internet backbone. This proposed model is cost-effective and more scalable and guarantees the QoS in mobile computing.

통합 망관리 시스템 지원을 위한 Managed Object Definition에 관한 연구

김종만,김태수,이광휘 창원대학교 정보통신연구소 2001 精報通信論文集 Vol.5 No.-

This paper presents a system for internetworking between different network management protocols. The internetworking system between SNMP and CMIP has been designed. SNMP has been used as a standard protocol in Internet while CMIP in OSI network. It is not easy to interoperate SNMP and CMIP because these protocols have several different aspects. So, definition method of integrated managed object to support several different domain managers in the grammar level has been proposed in this paper. In this paper, we propose technique to make new template, "macro" template. This template can include SNMP notation with minimum reformation. The package template is also extended and added for additional rules for SNMP domains. Through this approach, benefits of serving different services can be provided to several domain managers by modifying interfaces.