• 대한조선학회논문집
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• 제61권4호
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• pp.267-277
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• 2024

The Sortie Generation Rate (SGR) is a critical performance indicator for carrier-based aircraft and is a key factor for the carrier design process. This study aims to analyze the factors that affect SGR and establish a representative Sortie Generation Process (SGP) along with simulation results to calculate SGR for a naval ship equipped to carry aircraft. Detailed SGR factors are identified from the perspectives of the aircraft, aviation personnel, and aircraft carrier during the flight preparation stage, and the SGP is established accordingly. As a representative, Korean Navy's CVX basic design is chosen for detailed analysis. The physical dimension and spots for the deck design with time and probabilistic data of SGP are considered to develop a queueing network model for SGR calculation. To consider the specific probabilistic features, the model was solved with discrete event simulation tools(SimPy and AnyLogic) where the results show great agreement. Such findings on SGR factors and calculation are expected to be incorporated in the future development of SGR calculation algorithms and also present guidelines for proper design of aircraft carrier based on concrete operation concept.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2450-2469
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• 2018

In this paper, we develop a spatiotemporal model to analysis of cellular user in underlay D2D communication by using stochastic geometry and queuing theory. Firstly, by exploring stochastic geometry to model the user locations, we derive the probability that the SINR of cellular user in a predefined interval, which constrains the corresponding transmission rate of cellular user. Secondly, in contrast to the previous studies with full traffic models, we employ queueing theory to evaluate the performance parameters of dynamic traffic model and formulate the cellular user transmission mechanism as a M/G/1 queuing model. In the derivation, Embedded Markov chain is introduced to depict the stationary distribution of cellular user queue status. Thirdly, the expressions of performance metrics in terms of mean queue length, mean throughput, mean delay and mean dropping probability are obtained, respectively. Simulation results show the validity and rationality of the theoretical analysis under different channel conditions.

• 산업공학
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• 제14권3호
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• pp.263-271
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• 2001

MPLS LER is located at the boundary of MPLS domain as an ingress or an egress router and plays a role in connecting with the existing Internet. Among the components of the MPLS LER, forwarding engine(FE) is a key device which assigns a label to an IP packet by analyzing the destination address of its header in order to enter the MPLS domain, or restructures the cells from MPLS domain into IP packet by reversely processing. In this paper, we investigate the design of FE by analyzing the traffic performance of its components and estimate the IP packet processing capacity of a FE using queueing model and simulation. It is found that the maximum IP packet processing capacity of the Forwarding Engine is about 150,000 packets/sec.

• 전자공학회논문지A
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• 제31A권7호
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• pp.1-16
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• 1994

In this paper, we propose a new multiple access scheme for VSAT(Very Small Aperture Terminal) data communications. The proposed scheme has better performance in terms of delay throughput than Controlled Multiaccess Scheme which has excellent performance. The proposed scheme use the spare reservation method, adaptation method to offered load, and fixed bandwidth reservation method. In this paper, we analyze the performance using simple queueing model and present the simulation results. When network traffic is very low, the new scheme and the controlled multiaccess scheme have almost the same access delay characteristic. As the network load becomes higher, the new scheme's access delay gain becomes larger. Futhermore, even when the network traffic is very high it is possible to access satellite link within the delay similar to one round-trip delay. In addition to access delay performance enhancement, the new scheme has facility that supports fixed bandwidth reservation. So it shows more enhanced performance in the environment that stream traffic is dominant such as in VSAT communication environment.

• 한국컴퓨터정보학회논문지
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• 제10권2호
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• pp.123-132
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• 2005

본 논문에서는 기존의 무선 PKI 에서 키 교환방식의 키 교환 설정단계가 단순히 이산대수문제에 근거하여 수행되었지만 제안한 무선 PKI 인증구조의 상호인증과정에서는 키 교환 설정단계에 타원곡선을 적용하였다. 제안한 무선 PKI 구조 안에서의 핸드오버 방법은 CRL검색시간을 단축시킬 수 있으므로 기존의 방법에 비하여 단축된 핸드오버 처리시간을 보여준다 기존 알고리즘과 제안한 인증구조를 비교하여 실험해 보았을 때 인증 대기시간이 제안한 인증 기법이 모든 란경에서 기존 알고리즘보다 우수한 성능을 보였다.

• 응용통계연구
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• 제17권2호
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• pp.311-326
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• 2004

대다수의 TCP사용자들이 접근하여 병목현상을 보이는 두 개의 ECN/RED게이트 웨이에 대한 마코프 모형을 제시하고 분석하였다. 사용자의 수가 증가함에 따라, 각 게이트웨이의 버 피를 점유하는 사용자당 패킷수는 일정 한 상수들로 수렴 한다는 것을 보이고, 이 상수값을 구하는 알고리즘을 제시하였다.

• 한국통신학회논문지
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• 제23권6호
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• pp.1503-1513
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• 1998

This paper is related to a performance analysis of B-NT system, which is essential compositional equipment of B-ISDN access network. A simulator enabling performance analysis according to the change of network configuration topology and the change of user traffic is developed in this study. The developed B-NT, system simulator consists of graphic user interface module, simulation program automatic generator module, and B-NT system model library module. As examples of the results of performance analysis using the simulator, end-to-end user cell transmission delay time, queueing delay time in each system, and cell loss rate in the head node switch are presented. The simulator developed in this paper can be utilized in determining the network topology of B-NT system.

• Journal of Communications and Networks
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• 제14권5호
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• pp.510-517
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• 2012

This paper analyzes the performance of voice-over-Internet protocol (VoIP) services in terms of the system throughput, the packet delay, and the signaling overhead in a mobile WiMAX system with a hybrid automatic repeat request (HARQ) mechanism. Furthermore, a queueing analytical model is developed with due consideration of adaptive modulation and coding, the signaling overhead, and the retransmissions of erroneous packets. The arrival process is modeled as the sum of the arrival rate at the initial transmission queue and the retransmission queue, respectively. The service rate is calculated by taking the HARQ retransmissions into consideration. This paper also evaluates the performance of VoIP services in a mobile WiMAX system with and without persistent allocation; persistent allocation is a technique used to reduce the signaling overhead for connections with a periodic traffic pattern and a relatively fixed payload. As shown in the simulation results, the HARQ mechanism increases the system throughput as well as the signaling overhead and the packet delay.

• 산업공학
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• 제13권2호
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• pp.178-187
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• 2000

In this paper, we investigate the system performance when the voice traffic is constructed as the ATM Adaptation Layer type 2(AAL-2) and then it is transmitted to the Base Station Controller(BSC) from the Base Station Transceiver Subsystem(BTS) through El link in International Mobile Telecommunication-2000 (IMT-2000) network. For this purpose, we first briefly describe the architecture of the BTS and the BSC, and then model it as a queueing network. By simulation study, we present the required processing time at traffic control blocks and the timeout time which should be set for multiplexing the user packets in the LIU(Line Interface Unit). Further, we evaluate the performance of physical links and the timeout probability that user packets can not be multiplexed within the established timeout time, and the multiplexing gain. Finally, we present the number of voice users who can be simultaneously admitted on one El link and 99.9% value of the transmission delay from the Radio Channel Element(RCE) to the Selector & Transcoder Subsystem(STS).

• 한국통신학회논문지
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• 제19권3호
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• pp.434-441
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• 1994

본 논문에서는 생산 자동화 네트워크인 MAP에서 네트워크 관리 기능을 실현하기 위해 중용한 변수인 전송 지연과 버퍼크기 그리고 시스템의 안정도등의 트래픽 성능을 분석하였다. 네트워크 관리는 네트워크 상에서 통신이 정상적으로 수행되도록 자원의 제어 및 감독을 담당하는 것으로 네트워크 운영시 필수적으로 요구되는 기능이다. 그러나 MAP 네트워크는 운영시 빠른 응담성을 요구하기 때문에 네트워크 관리 시스템을 구현하여 운영하기 위해서는 네트워크 관리 활동으로 인한 영향을 고려하여야 한다. 네트워크 관리 시스템 동작시 발생하는 불균일한 트래픽을 분석하기 위해, 사이클릭 큐잉 모델을 이용해 해석적 방법과 시뮬레이션을 수행하여 대기 지연 시간과 버퍼 크기를 구했으며, 네트워크 관리 활동에 따른 시스템의 안정도를 분석하였다.