• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2011년도 정기 학술대회
• /
• pp.429-432
• /
• 2011

과적차량은 도로 및 교량 구조물과 도로 횡단 시설물 등에 손상요인으로 작용하며 기존의 단속 시스템은 축조작 및 인력부족등 많은 문제점을 내포하고 있어서 이에 대한 대처방안이 요구되고 있다. 이에 본 논문에서는 주행중인 과적차량의 지능형 임베디드 단속 시스템 개발을 위하여 유전자 알고리즘 기법을 적용, 도로자체를 저울로 하여 주행중인 차량의 하중 및 주행정보를 분석을 연구하였으며 이를 통하여 효율적인 과적 단속이 이루어 질 수 있다고 판단된다. 또한 USN구성을 위한 임베디드 센서와 함께 Internal/External Network의 무선화 시스템을 통한 사용자 중심의 시스템을 구축하는 것이 최종 목적이므로 향후 WCDMA/HSDPA를 이용한 External Network의 구성과 실제 과적 단속 적용을 위하여 Test Bed를 통한 실험이 실시되어야 할 것이다.

• 한국정보처리학회논문지
• /
• 제6권1호
• /
• pp.49-56
• /
• 1999

Distributed object Computing, owing to the development of distributed computing, has improved the performance of distributed processing conducted between homogeneous and heterogeneous systems in network. However, it has failed to solve fundamental problems such as network overload and enormous requests demands by servers and clients. In this paper, we propose to design and implement an Object Migration system that uses the java language to tackle the mentioned problems. As the first step of the implementation of the system, we justify the characteristics of t도 mobile object model that keeps codes and states of an object. Implemented Object Migration System would accept objects being migrated to a specific node and support the virtual place in which objects could be executed automatically. Therefore, the Object Migration system we suggest could not only solve problems imposed to traditional distributed computing but also offer transparency of object migration between homogeneous and heterogeneous systems.

• 정보처리학회논문지A
• /
• 제11A권3호
• /
• pp.181-188
• /
• 2004

인터넷 기반 분산/병렬 처리 시스템인 PDP(Parallel/Distributed Processing)는 인터넷의 유휴상태 호스트들을 이용하여 대용량 작업을 병렬로 처리해서 전체 수행 시간을 감소시킨다. 본 연구에서는 실시간 네트워크 모니터링을 활용하여 수시로 변화하는 네트워크 환경에 적응하여 병렬/분산 처리되는 방안을 제안한다. 실시간 네트워크 모니터링 정보를 PDP 주요 핵심 알고리즘들에 적용하여 네트워크 과부하 및 결함으로 발생하는 작업 지연 요소에 적응적으로 대처함으로써 전체 성능이 향상됨을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권7호
• /
• pp.1721-1736
• /
• 2013

Black and gray hole attack is one kind of routing disturbing attacks and can bring great damage to the network. As a result, an efficient algorithm to detect black and gray attack is important. This paper demonstrate an adaptive approach to detecting black and gray hole attacks in ad hoc network based on a cross layer design. In network layer, we proposed a path-based method to overhear the next hop's action. This scheme does not send out extra control packets and saves the system resources of the detecting node. In MAC layer, a collision rate reporting system is established to estimate dynamic detecting threshold so as to lower the false positive rate under high network overload. We choose DSR protocol to test our algorithm and ns-2 as our simulation tool. Our experiment result verifies our theory: the average detection rate is above 90% and the false positive rate is below 10%. Moreover, the adaptive threshold strategy contributes to decrease the false positive rate.

• 센서학회지
• /
• 제16권5호
• /
• pp.361-368
• /
• 2007

Small size real-time ECG signal analysis function by QRS-complex detection was put into sensor nodes. Wireless sensor nodes attached on the patient’s body transmit ECG data continuously in normal u-healthcare system. So there are heavy communication traffics between sensor nodes and gateways. New developed platform for real-time analysis of ECG signals on sensor node can be used as an advanced diagnosis and alarming system for healthcare. Sensor node does not need to transmit ECG data all the time in wireless sensor network and to server PC via gateway. When sensor node detects suspicion or abnormality in ECG, then the ECG data in the network was transmitted to the server PC for further powerful analysis. This system can reduce data packet overload and save some power in wireless sensor network. It can also increase the server performance.

• 한국정보시스템학회지:정보시스템연구
• /
• 제24권1호
• /
• pp.147-168
• /
• 2015

Why people reduce or stop using social network services(SNS), which are regarded as a mean of relationship and communication, unlike the early trend? To explain the phenomenon, this study tries to predict psychological decision making process of users from perspectives of cognitive dissonance theory. From this perspective, this study attempted an integrative approach that reflected 'User's literacy' indicating the ability of individuals to use SNS, and 'negative mass media influence' such as media reports on side effects or the bad experiences of acquaintances, along with the 3 factors used in the SNS Prior research. This study conducted an empirical analysis by surveying 256 facebook users, and the major findings are as follows:- First, Social-overload, complexity, uncertainty and negative media influence are significantly affect dissonance on the use of SNS. Second, Dissonance on the use of SNS significantly affects the behavior that possibly reduces and limits the use of SNS. In other words, the users who have experienced psychological dissonance respond passively by avoiding the use of SNS to resolve the dissonance. Third, the moderating effect of User's literacy wasn't a significant. This study presents a clue to understand psychological decision making process of use of SNS and a guideline for establishing practical strategies. In addition, it is important to note that this study contributes to expansion of theoretical discussion about usage.

• Journal of Communications and Networks
• /
• 제18권3호
• /
• pp.513-522
• /
• 2016

We propose a mechanism for monitoring load in quality of service (QoS)-enabled wireless networks and show how it can be used for network management as well as for dynamic pricing. Mobile network traffic, especially video, has grown exponentially over the last few years and it is anticipated that this trend will continue into the future. Driving factors include the availability of new affordable, smart devices, such as smart-phones and tablets, together with the expectation of high quality user experience for video as one would obtain at home. Although new technologies such as long term evolution (LTE) are expected to help satisfy this demand, the fact is that several other mechanisms will be needed to manage overload and congestion in the network. Therefore, the efficient management of the expected huge data traffic demands is critical if operators are to maintain acceptable service quality while making a profit. In the current work, we address this issue by first investigating how the network load can be accurately monitored and then we show how this load metric can then be used to provide creative pricing plans. In addition, we describe its applications to features like traffic offloading and user satisfaction tracking.

• 정보과학회 논문지
• /
• 제44권10호
• /
• pp.1071-1080
• /
• 2017

오늘날 복잡한 네트워크 망을 가지게 됨에 따라 네트워크 기기들의 자산식별은 관리 및 보안관점에서 중요한 사항으로 대두되고 있다. 이러한 자산들은 네트워크 망에 연결되어 있기 때문에 네트워크망 구조를 알아내고, 각 자산의 위치 및 연결 상태를 확인하는 것 또한 중요하다. 이는 네트워크 구조상의 취약점들을 밝혀내는데 사용되어지고, 이를 통하여 취약점을 보완할 수 있다. 하지만 적은 리소스를 가지는 사물인터넷의 네트워크 망에서는 네트워크 구조를 알아내기 위하여 모니터들이 보내는 Traceroute 패킷이 사물인터넷 기기들에게 과부하를 줄 수 있다. 이를 위하여 본 논문에서는 기존에 사용 되던 더블 트리 알고리즘을 효과적으로 발전시킴으로써 사물인터넷이 이루는 네트워크 망의 부하를 줄인다. 이러한 부하 균형을 이루기 위하여 이 논문에서는 새로운 목적지 매칭 알고리즘을 제시하고, 통계학적으로 현재 탐색하고 있는 경로와 가장 겹치지 않은 경로로 탐색을 시도한다. 이를 통해서 네트워크의 부하 균형을 이루고, 부가적으로 모니터의 리소스 사용을 균등하게 한다.

• 한국항행학회논문지
• /
• 제14권6호
• /
• pp.996-1001
• /
• 2010

본 논문에서는 Mobile IPTV의 서비스를 위한 네트워크 선택 알고리즘을 제안하고 처리속도가 낮은 단말기의 부하를 줄이기 위한 계층별 처리 시스템을 구현하였다. 제안한 알고리즘은 새로운 사용자가 네트워크에 접속할 때 잔여 대역폭, 네트워크 비용, 신호세기를 이용하는 계산식에서 나온 우선순위 값으로 네트워크를 선택한다. 처리속도가 낮은 단말기의 응용계층에서 네트워크 선택과 TV서비스 제공을 모두하면 시스템 부하로 서비스의 품질이 낮아지게 되므로 네트워크 선택과 TV 서비스기능을 계층별로 나누어 처리하는 시스템을 구현하였다. 실험결과 사용자가 직접 네트워크를 선택하는 방법에서는 대역폭 할당을 위한 대기시간이 존재하고, 대역폭을 모두 소진한 경우 대역폭 할당을 위한 대기 시간이 길어지는 반면 본 논문에서 제안한 우선순위를 이용한 네트워크 선택 알고리즘을 이용할 경우 여러 네트워크 중 상태가 좋은 네트워크를 선택하기 때문에 데이터 전송속도가 평균적으로 유지가 되고 대역폭 할당 대기시간이 낮아지는 것을 확인하였다.

• International Journal of Computer Science & Network Security
• /
• 제23권1호
• /
• pp.153-163
• /
• 2023

This study is situated in the context of intelligent transport systems, where in-vehicle devices assist drivers to avoid accidents and therefore improve road safety. The vehicles present in a given area form an ad' hoc network of vehicles called vehicular ad' hoc network. In this type of network, the nodes are mobile vehicles and the messages exchanged are messages to warn about obstacles that may hinder the correct driving. Node mobilities make it impossible for inter-node communication to be end-to-end. Recognizing this characteristic has led to delay-tolerant vehicular networks. Embedded devices have small buffers (memory) to hold messages that a node needs to transmit when no other node is within its visibility range for transmission. The performance of a vehicular delay-tolerant network is closely tied to the successful management of the nodes' transit buffer. In this paper, we propose a message transit buffer management model for nodes in vehicular delay tolerant networks. This model consists in setting up, on the one hand, a policy of dropping messages from the buffer when the buffer is full and must receive a new message. This drop policy is based on the concept of intermediate node to destination, queues and priority class of service. It is also based on the properties of the message (size, weight, number of hops, number of replications, remaining time-to-live, etc.). On the other hand, the model defines the policy for selecting the message to be transmitted. The proposed model was evaluated with the ONE opportunistic network simulator based on a 4000m x 4000m area of downtown Bouaké in Côte d'Ivoire. The map data were imported using the Open Street Map tool. The results obtained show that our model improves the delivery ratio of security alert messages, reduces their delivery delay and network overload compared to the existing model. This improvement in communication within a network of vehicles can contribute to the improvement of road safety.