• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.1
• /
• pp.35-40
• /
• 2011

In this paper, we compare and analyze data aggregation methods based on event area in wireless sensor networks. Data aggregation methods consist of two methods: the direct transmission method and the aggregation node method. The direct aggregation method has some problems that are data redundancy and increasing network traffic as all nodes transmit own data to neighbor nodes regardless of same data. On the other hand the aggregation node method which aggregate neighbor's data can prevent the data redundancy and reduce the data. This method is based on location of nodes. This means that the aggregation node can be selected the nearest node from a sink or the centered node of event area. So, we describe the benefits of data aggregation methods that make up for the weak points of direct data dissemination of sensor nodes. We measure energy consumption of the existing ways on data aggregation selection by increasing event area. To achieve this, we calculated the distance between an event node and the aggregation node and the distance between the aggregation node and a sink node. And we defined the equations for distance. Using these equations with energy model for sensor networks, we could find the energy consumption of each method.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.1
• /
• pp.10-16
• /
• 2008

The Manifestation Consolidation System(MFCS) has made a peat contribution to effective improvement of distribution industry. To save distribution expenses and the time needed to record reports, more simplified system is being used for which overlapped or unnecessary transmitted items in taking care of goods are decreased. To become a center of Asian distribution information, our country has to prepare for the base of the MFCS and use it effectively Therefore, for an effective management of the MFCS, this study examines a procedure that takes care of goods in the MFCS, presents a future-model of the MFCS, and analyses classification of tasks relating to export and import and titles of electronic documents. In conclusion, this study aims at presenting an interpretative base of the MFCS in a practical viewpoint rather than presenting its technical direction.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.1
• /
• pp.71-76
• /
• 2013

In this paper, end-to-end performances for some VoIP traffics are measured and analyzed over MANET(Mobile Ad-hoc Networks) with packet aggregation transmission under blackhole attacks. A VoIP simulator based on NS-2 is used for performance measure. In the simulation, MOS, call connection ratio, network delay and packet loss rate are measured for end-to-end transmission performance. With analysis of measured data, characteristics of each traffics for performance parameters of packet aggregation transmission is showed on MANET under blackhole attack, As a results of this paper, some considerations be required for packet aggregation transmission are suggested to implement VoIP services on MANET under blackhole attacks.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.7
• /
• pp.1845-1857
• /
• 1996

An alarm gathering interface equipment has been developed to collect the hardware failure activities in 1$1, 024\times1, 024$ ATM switching system. The equipment use 8-bit microprocessor and ELA-232C port, and is fabricated in a single board, which called Alarm Gathering Interface board Assembly(AGIA). It is programmed to ensure flexibility in modification and expansion of the system capability. The performance is successfully proved through communication test with hardware blocks or modules consisting a ATM switching system, these techniques can be used to develop operation and maintenance functions for more superior ATM switching system in the near future. we additionally have presented some items for further study on alarm subsystem often ATM switching system.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.9
• /
• pp.3002-3010
• /
• 2000

ATM forum defined several ATM oriented services such as ABR, VBR, CBR, UBR, and others. Among them, ABR service is considered as one of the most appropriate ones in the LAN environment. ABR controls network traffic by using RM cells according to ATM forum standard. In particular, the point-to-multipoint ABR service in general uses consolidation algorithms to solve feedback implosion at the branch point. Consolidation algorithms alleviate propagation delay and network congestion problem: thus, the efficiency of consolidation algorithm is closely related to the network performance. In this paper, we describe the limitation of existing consolidation algorithms based on thorough analysis, and then propose an algorithm that performs better than the existing algorithms. We show that the proposed algorithm improves network performance through a parametric simulation, In our simulation the performance measure is the cell rate which is controlled by exploiting the congestion depth. We also found that the proposed algorithm not only improves efficiency of network, but also eliminates the consolidation noise.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.6
• /
• pp.689-694
• /
• 2014

DDoS attacks on MANET makes disable any node which support network function, cause critical results as a stopping of entire network service or separation to some parts. Packet aggregation, which gather some pieces of short length into a certain length of data, improves transmission performances on MANETs. In this paper, some effects on transmission performance of packet aggregation transmission be caused by DDoS Attacks are measured and analyzed in point of end-to-end level. MANET simulator, based on NS-2, is used for measurement end-to-end performances. MOS, connection rate, delay and packet loss rate is used as performance parameters. VoIP traffic is used for object service measurement. Finally, it is suggested that number of packet aggregation is more then 4 for keeping the transmission quality over MANETs under DDoS attacks.

• Electronics and Telecommunications Trends
• /
• v.13 no.6 s.54
• /
• pp.34-45
• /
• 1998

HANbit ACE ATM 교환기에서 장애 상태의 경보 소스를 취합하기 위하여 소프트웨어에 의한 방법과 하드웨어에 의한 방법 두 가지를 병행하여 사용한다. 각 제어 장치가 가능한 자신의 제어 아래에 있는 자원에 대하여 소프트웨어에 의한 방법으로 경보 소스를 취합하고, 소프트웨어에 의한 방법으로 취합 불가능한 일부 하드웨어 장애 경보는 각각의 제어 장치가 직접 처리하며 하드웨어 경보 수집은 가능한 최소화 하였다. 본 고에서는 소프트웨어와 하드웨어에 의한 방법으로 수집된 장애 경보의 장애소스를 주기적으로 감시하여 장애가 발생한 경우 감지된 장애에 대한 장애 발생 위치 및 장애 내용을 출력, 장애 메시지로 운용자에게 알려주며, 아울러 그래픽 표현 기능을 이용한 가시장애, 멀티미디어를 사용한 가청장애로 장애표시를 하여 시스템 유지보수를 용이하게 하는 구조를 가지는 ATM 교환기의 소프트웨어 및 하드웨어에 의한 경보 처리 시스템에 대하여 논하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2004.04a
• /
• pp.474-476
• /
• 2004

본 논문에서는 교무업무지원시스템의 하나인 WDCMS(웹기반데이터취합관리시스템)를 학교현장에 실제로 적용시켜 봄으로써, ICT(정보통신기술) 기반으로 일하는 방식을 개선하고 일상적으로 반복되고 중복되는 업무에서 탈피하고 지금까지 모든 내ㆍ외부 문서처리(공문, 비 공문서)의 수작업과 결재과정의 시간과 인적자원의 낭비를 개선함은 물론 업무의 정확성 및 효율성을 높여 신속한 업무처리로 교원의 업무 경감과 교사의 주된 업무인 교수 ㆍ학습활동에 전념 할 수 있도록 교육 여건을 개선하고, 나아가 교육 정보 자료의 효과적인 관리 및 활용으로 경쟁력 있는 선진교육 환경을 구축하고자 한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.5 no.3
• /
• pp.275-280
• /
• 2010

In this paper, VoIP(Voice over Internet Protocol) transmission performance for MANET(Mobile Ad-hoc Networks) is improved and analyzed with packet aggregation scheme which is aggregating some of short length packets to one large packet and sending to networks. VoIP simulator based on NS(Network Simulator)-2 is implemented and used to measure performance of VoIP traffic transmission. In this simulation, VoIP traffics are generated with parameters of some codes such as G.711, G.729A, GSM.AMR and iBLC. MOS(Mean Opinion Score), end-to-end network delay, packet loss rate and transmission bandwidth are measured. Performance improvements of 98% for MOS, 6.4times for end-to-end network delay, 32times for packet loss rate is shown as simulation results. On the other hand, transmission bandwidth is increased about maximum 10%. Finally, VoIP implementation guide for the performance with packet aggregation is suggested.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.5
• /
• pp.161-166
• /
• 2010

Conventional Or Rule decide final sensing result depending on all of SU making sensing result. So Conventional Or Rule must be combined all of local result to decide PU absent or not. But Proposed Or Rule is not needed all of local result depending on each of SU of local result. So Proposed Or Rule can reduce decision time. In this Paper, we verify proposed Or Rule using simulation tool similar with matlab. And we can calculate false alarm probability and miss detection probability of proposed Or rule and conventional Or rule.