• 전자공학회논문지A
• /
• 제32A권9호
• /
• pp.1184-1201
• /
• 1995

Two multiple access protocols are proposed for a multichannel WDM optical fibre local area network or metropolitan area network in which users are interconnected using a passive star topology. Each user has a single tunable transmitter and a single tunable receiver. A transmitter sends a control packet before its data packet transmission so that its intended receivers can tune to the proper data channel wavelength. The maximum throughput of the proposed protocols are independent of the effective normalized propagation delay which may include the transmitter and receiver tuning times and the processing delays. The maximum throughputs of the protocols are analyzed and compared with those of the existing ones by numerical examples. The message delay of the R- Aloha/synchronous N-server switch protocol which is suitable for the queued users is also analyzed.

• 인터넷정보학회논문지
• /
• 제4권5호
• /
• pp.51-60
• /
• 2003

비동기 반복 알고리즘은 부하 불균형 및 컴퓨터 노드 간의 전송 지연에 의한 병렬 알고리즘의 성능 저하를 완화하는 하나의 방법인데, 이는 노드들 간의 비대칭적 데이터 전송을 필요로 한다 본 논문에서는 분산 메모리 시스템 상에서 MPMD 방식으로 노드당 별도의 서버 프로세스를 추가로 생성하여 비대칭적 전송을 구현하고, 노드당 하나의 프로세스를 생성하는 SPMD 방식과 비교하며 그 장단점에 대해 논의한다.

• 한국정보통신학회논문지
• /
• 제24권1호
• /
• pp.145-148
• /
• 2020

Wearable computing is growing rapidly as research on body area communication network using wireless sensor network technology is actively conducted. In particular, there is an increasing interest in smart clothing measuring unrestrained and insensitive bio signals, and research is being actively conducted. However, research on smart clothing is mainly based on 1: 1 wireless communication. In this paper, we propose a multi-access monitoring system that can measure bio-signals by multiple users wearing smart clothing. The proposed system consists of wireless access device, multiple access control server and monitoring system. It also provides a service that allows multiple users to monitor and measure bio signals at the same time.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2017년도 춘계학술발표대회
• /
• pp.315-318
• /
• 2017

Nowadays, Distributed Denial of Service (DDoS) attacks have gained increasing popularity and have been a major factor in a number of massive cyber-attacks. It could easily exhaust the computing and communicating resources of a victim within a short period of time. Therefore, we have to find the method to detect and prevent the DDoS attack. Recently, there have been some researches that provide the methods to resolve above problem, but it still gets some limitations such as low performance of detecting and preventing, scope of method, most of them just use on cloud server instead of network, and the reliability in the network. In this paper, we propose solutions for (1) handling multiple DDoS attacks from multiple IP address and (2) handling the suspicious attacks in the network. For the first solution, we assume that there are multiple attacks from many sources at a times, it should be handled to avoid the conflict when we setup the preventing rule to switches. In the other, there are many attacks traffic with the low volume and same destination address. Although the traffic at each node is not much, the traffic at the destination is much more. So it is hard to detect that suspicious traffic with the sampling based method at each node, our method reroute the traffic to another server and make the analysis to check it deeply.

• 정보보호학회논문지
• /
• 제27권2호
• /
• pp.293-303
• /
• 2017

생체인식 기술을 이용하여 기존의 패스워드를 대체하기 위한 FIDO(Fast IDentity Online)[1,7] 기술이 빠르게 성장하고 있다. FIDO 기술은 생체인식 기술을 이용한 편리한 사용자 인증과 스마트카드 기술을 이용한 안전한 키관리 기능을 제공하지만 사용자 신원인증 기술이 함께 제공되지 않아 사용자가 FIDO 기기를 원격 서버에 초기 등록하는 과정에서는 기존의 전통적인 신원인증 방식을 이용할 수밖에 없다. K-FIDO[3]는 이런 단점을 해결하기 위하여 FIDO 기술과 인증서기반 기술을 하나의 기기에 접목시킨 것으로 사용자의 초기등록 과정에서 인증서 기반 인증을 이용할 수 있게 하였다. 그런데 사용자들이 복수의 K-FIDO 기기를 사용하는 유비쿼터스 환경이 빠르게 도래할 것으로 예상되는데, 이런 환경에서는 만일 기존의 방식대로 하나의 인증서를 여러 기기에 복사하여 사용하거나, 기기별로 별도의 인증서를 발급받아 사용하게 된다면 많은 문제가 발생할 것으로 예상된다. 본 논문에서는 자체확장인증[4] 방식을 이용하여 복수 K-FIDO 기기 환경에서 인증키 관리의 편의성을 향상시킬 수 있는 방안을 제시한다.

• 전자통신동향분석
• /
• 제33권1호
• /
• pp.34-44
• /
• 2018

In this paper, we describe a FIDO universal authentication system based on a Blockchain that can share the user's FIDO authentication information between the application services of multiple domains without the use of a server. In addition we provide a method to query the FIDO authentication information of the user recorded in the Blockchain using only the user's service ID. Therefore, even if the user executes the FIDO registration process only once, the user can use the FIDO authentication service of another application service without repeating an additional FIDO registration procedure, and the service provider can securely share and utilize the FIDO authentication information of the user without the use of a trusted third party, thereby lowering the deployment and maintenance costs of the FIDO server.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.718-723
• /
• 2005

In this paper, we propose the collaborative design system with which we can simultaneously modify the actual 3D CAD model by the remote control and have interaction on it. It enables instantaneous decision making among the multiple disciplines in distributed locations using the function of simultaneous access and video conference. It also provides the method of managing the consistency between design entities. This system consists of Collaborative Management Server, File Server, Solid Modeler Client, Remote Control Module and Client Module.

• 한국정보전자통신기술학회논문지
• /
• 제11권1호
• /
• pp.26-33
• /
• 2018

A web application running on the Internet is causing many difficulties for a program developer, and it requires to process multiple sessions at the same time due to the occurrence of excessive traffic. Web applications should be able to process concurrent requests efficiently and in real time. Node.js is a single-threaded server-side JavaScript environment implemented in C and C ++ as one of the latest frameworks to implement event models across the entire stack. Nodes implement JavaScript quickly and robust to achieve the best performance using a JavaScript V8 engine developed by Google. In this paper, it will be explained the operation principle of Node.js, which is a lightweight real-time web server that can be implemented in JavaScript for real-time responsive web applications. In addition, this application was practically implemented through automatic alignment system for group scheduling to demonstrate event-based real-time response web processing.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 C
• /
• pp.1120-1122
• /
• 1999

This paper introduces a clustering for Central Control System in New Distribution Automation System. There are three primary benefits to use clustering: improved availability, easier manageability and more cost-effective scalability. Availability: Clustering can automatically detect the failure of an application or server and quickly restart it on a surviving server. Clients only experience a momentary pause in service. Manageability: Clustering lets administrators quickly inspect the status of all cluster resources and easily move workload around onto different servers within a cluster. Scalability: Applications can use the Clustering services through the MSCS Application Programming Interface(API) to do dynamic load balancing and scale across multiple servers within a cluster.

• Journal of applied mathematics & informatics
• /
• 제33권1_2호
• /
• pp.77-87
• /
• 2015

Parallel lines are often used to increase production rate in many manufacturing systems where the main line splits into several lines in parallel, and after some operations, they merge into a main line again. Queueing networks with finite buffers have been widely used for modeling and analyzing manufacturing systems. This paper provides an approximation technique for multi-server two-stage networks with merge configuration and blocking which will be a building block for analysis of general manufacturing systems with parallel lines and merge configuration. The main idea of the method is to decompose the original system into subsystems that have two service stations with multiple servers, two buffers and external arrivals to the second stage are allowed. The subsystems are modeled by level dependent quasi-birth-and-death (LDQBD) process.