• Journal of Communications and Networks
• /
• 제3권4호
• /
• pp.383-395
• /
• 2001

Recent measurement and simulation studies have revealed that wide area network traffic displays complex statistical characteristics-possibly multifractal scaling-on fine timescales, in addition to the well-known properly of self-similar scaling on coarser timescales. In this paper we investigate the performance and network engineering significance of these fine timescale features using measured TCP anti MPEG2 video traces, queueing simulations and analytical arguments. We demonstrate that the fine timescale features can affect performance substantially at low and intermediate utilizations, while the longer timescale self-similarity is important at intermediate and high utilizations. We relate the fine timescale structure in the measured TCP traces to flow controls, and show that UDP traffic-which is not flow controlled-lacks such fine timescale structure. Likewise we relate the fine timescale structure in video MPEG2 traces to sub-frame encoding. We show that it is possibly to construct a relatively parsimonious multi-fractal cascade model of fine timescale features that matches the queueing performance of both the TCP and video traces. We outline an analytical method ta estimate performance for traffic that is self-similar on coarse timescales and multi-fractal on fine timescales, and show that the engineering problem of setting safe operating points for planning or admission controls can be significantly influenced by fine timescale fluctuations in network traffic. The work reported here can be used to model the relevant characteristics of wide area traffic across a full range of engineering timescales, and can be the basis of more accurate network performance analysis and engineering.

• 한국통신학회논문지
• /
• 제31권5A호
• /
• pp.441-450
• /
• 2006

최근 인터넷 사용자가 급증함에 따라 전체 인터넷 트래픽의 90%이상을 차지하는 IP 트래픽이 통신망 성능에 미치는 영향은 매우 크다. 따라서 효율적인 망의 설계와 설계된 망의 정확한 성능 평가를 위하여 IP 트래픽의 특성을 반영한 자기유사성(self-similarity) 트래픽 발생기의 설계는 매우 중요하다. 본 논문에서는 OPNET을 이용하여 자기유사성 트래픽 발생기를 설계한다. 이를 위해 Pareto 분포를 갖는 ON-OFF 소스를 이용하고, 이를 다중화하여 중첩시킴으로써 자기유사성의 특성을 구현하였다. 또한 구현한 자기유사성 트래픽 발생기의 성능 평가를 위하여 다양한 통계학적인 접근방법을 통해 자기유사성의 특성을 분석 검증하고, 입력부하 및 다중화 된 소스의 개수에 따른 영향을 분석하였다. 설계된 자기유사성 트래픽 발생기는 유무선 통신망 모델 구현 및 성능 평가 시 IP 트래픽 발생기로 활용될 수 있으며, 자기유사성 트래픽 모델링에서 요구되는 구체적인 파라미터 값의 결정에도 도움이 될 것으로 기대된다.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권5호
• /
• pp.1065-1077
• /
• 2021

Directorate of Traffic of the Regional Police D.I. Yogyakarta as part of the Indonesian Republic Police (Polri) institution also experiences problems related to the performance of police members as well as the Polri institution in general. The problems which relate to the police performance are influenced by various factors such as low compensation and as a result low motivation in the work environment of Directorate of Traffic of the Regional Police D.I. Yogyakarta. Therefore, the objective of this study is to empirically test and prove the effect of the work environment and compensation on work motivation and police performance of Directorate of Traffic of the Regional Police D.I. Yogyakarta, Indonesia. This study used a survey method for collecting data. By using proportional stratified random sampling, 143 members of Directorate of Traffic of the Regional Police D.I. Yogyakarta were selected as the respondents. The results of this study indicate that work environment has a positive effect on work motivation, police performance as well as compensation on work motivation and police performance. In addition, work motivation has a positive effect on police performance. Thus, this study concludes that work motivation mediates the effect of work environment and compensation on police performance.

• 전자공학회논문지B
• /
• 제33B권6호
• /
• pp.136-148
• /
• 1996

In this paper, we analyze the traffic characteristics in microcell and macrocell overlaid PCS system which process voice and dta calls separately each others. in this system, data calls are delayed in queue when all of channels are occupied, while voice calls are bolcked in that case. For this, we calculated inter-microcell handoff area dwelling time distribution and handoff area dwelling time distribution between microcell and macrocell. We analyze traffic performance using this results. We used M/M/C/K model, and analyzed traffic performance of macrocell with handoff area variation of microcell.

• Journal of Communications and Networks
• /
• 제18권1호
• /
• pp.123-131
• /
• 2016

The high-availability seamless redundancy (HSR) protocol is one of the most important redundancy IEC standards that has garnered a great deal of attention because it offers a redundancy with zero recovery time, which is a feature that is required by most of the modern substation, smart grid, and industrial field applications. However, the HSR protocol consumes a lot of network bandwidth compared to the Ethernet standard. This is due to the duplication process for every sent frame in the HSR networks. In this paper, a novel algorithm known as the reducing multicast traffic (RMT) is presented to reduce the unnecessary redundant multicast traffic in HSR networks by limiting the spreading of the multicast traffic to only the rings that have members associated with that traffic instead of spreading the traffic into all the network parts, as occurs in the standard HSR protocol. The mathematical and the simulation analyses show that the RMT algorithm offers a traffic reduction percentage with a range of about 60-87% compared to the standard HSR protocol. Consequently, the RMT algorithm will increase the network performance by freeing more bandwidth so as to reduce HSR network congestion and also to minimize any intervention from the network administrator that would be required when using traditional traffic filtering techniques.

• Journal of information and communication convergence engineering
• /
• 제9권5호
• /
• pp.551-555
• /
• 2011

Optical packet switching is a promising technology, which can integrate both data and optical network. In this paper, we present a comparative study of various traffic arrival approaches in WDM packet switches. The comparison is made based on packet loss rate and average delay under uniform and self-similar Pareto traffic. Computer simulations are performed in order to obtain the switch performance metrics. Study shows that burstiness of data traffic has a strong negative impact in the performance of WDM packet switches.

• 전기학회논문지P
• /
• 제62권3호
• /
• pp.111-116
• /
• 2013

Noise problem that occurs on the road is raising a lot of problems in the economic, social and environmental aspects. The objective of this paper is to propose ANC(active noise cancellation)-based road traffic noise reduction algorithm-model which can reduce noise by generating frequency opposed to noise sources to improve and complement the problem that existing physical form of a noise barrier. In this paper, we measured the noise characteristic from collection of two difference car noise also ANC simulation has been performed by using road traffic noises input. In order to compare the control performance, we performed noise reduction simulation of ANC by filtered-X LMS algorithm and delayed control signal injection. As a result of this simulation, we confirmed that convergence performance and noise decrease effect to the filtered-X LMS algorithm by inputting the road traffic noise.

• 한국통신학회논문지
• /
• 제22권3호
• /
• pp.593-603
• /
• 1997

Connection admission decision in ATM networks requires decision made in real time using fast algorithm. It is difficult to construct a model of the multiplexed traffic and thus, approximation of the traffic load is necessary. In this paper, we propose a measurement-based dynamic CAC(Connection admission Control) in ATM(Asynchronous Transfer Mode) networks, which observes current traffic by the moving window and set the window size to the value which is computed from the measured cell loss amount. It is based on the measurements of the traffic load over an admission period that is load enough to reflect the current traffic behavior instead of analytic modeling. And, the dynamic reallocation of bandwidth for each class leads to effective bandwidth utilization. The performance of proposed method is analyzed through computer simulation. The performance of proposed method is analyzed by using SIMAN simulation package and FORTRAN language. As can be seen in the simulation result, cell loss performance and bandwidth utilization have been increased.

• Management Science and Financial Engineering
• /
• 제4권2호
• /
• pp.43-58
• /
• 1998

Packet switch is a key component in high speed digital networks. This paper investigates congestion phenomena in the packet switching with input buffers. For large value of switch size N, mathematical models have been developed to analyze asymptotic maximum switch throughput under nonuniform traffic. Simulation study has also been done for small values of finite N. The rapid convergence of the switch performance with finite switch size to asymptotic solutions implies that asymptotic analytical solutions approximate very closely to maximum throughputs for reasonably large but finite N. Numerical examples show that non-uniformity in traffic pattern could result in serious degradation in packet switch performance, while the maximum switch throughput is 0.586 when the traffic load is uniform over the output trunks. Window scheduling policy seems to work only when the traffic is relatively uniformly distributed. As traffic non-uniformity increases, the effect of window size on throughput is getting mediocre.

• ETRI Journal
• /
• 제42권3호
• /
• pp.366-375
• /
• 2020

The network traffic prediction of a smart substation is key in strengthening its system security protection. To improve the performance of its traffic prediction, in this paper, we propose an improved gravitational search algorithm (IGSA), then introduce the IGSA into a wavelet neural network (WNN), iteratively optimize the initial connection weighting, scalability factor, and shift factor, and establish a smart substation network traffic prediction model based on the IGSA-WNN. A comparative analysis of the experimental results shows that the performance of the IGSA-WNN-based prediction model further improves the convergence velocity and prediction accuracy, and that the proposed model solves the deficiency issues of the original WNN, such as slow convergence velocity and ease of falling into a locally optimal solution; thus, it is a better smart substation network traffic prediction model.