• Journal of Internet Computing and Services
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• v.14 no.3
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• pp.67-79
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• 2013

In wireless networks, efficient mobility management to support of mobile users is very important. Several mobility management schemeshave been proposed with the aim of reducing the signaling traffic of MN(Mobile Node). Among them, PMIPv6 (Proxy Mobile IPv6) is similar with host-based mobility management protocols but MN does not require any process for mobility. By introducing new mobile agent like MAG (Mobile Access Gateway) and LMA (Local Mobility Anchor), it provides IP mobility to MN. In this paper, we propose the analytical model to evaluate the mean signalingdelay and the mean bandwidth according to the type of MN mobility. As a result of mathematical analysis, MF-PMIP (Multicasting-based FastPMIP) outperforms compared to F-PMIP and PMIP in terms of parameters for the performance evaluation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.277-283
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• 1995

In the study, an accuracy of earthwork volume is evaluated according to different methods of the calculation with different criteria. The criteria applied to this study are a interpolation method, a grid intavals and the method of earthwork evaluation. A numerical test has performed on two different terrain models with four different methods of calculation in the earthwork volume and two different grid intervals. The end area method, prismoidal formular, Simpson's formular, and middle area method are applied to the calculation of the earthwork volume. As a result of this study, it is showed that the moving average method with the first order term gives the most accurate result in interpolation, and that also the prismoidal formular and Simpson's formular gives more accurate result than average and area method and middle area method in the calculation of earthwork volume.

• Convergence Security Journal
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• v.11 no.3
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• pp.19-24
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• 2011

Software failure time presented in the literature exhibit either constant monotonic increasing or monotonic decreasing, For data analysis of software reliability model, data scale tools of trend analysis are developed. The methods of trend analysis are arithmetic mean test and Laplace trend test. Trend analysis only offer information of outline content. In this paper, we discuss forecasting failure time case of failure time censoring. In this study, time series analys is used in the simple moving average and weighted moving averages, exponential smoothing method for predict the future failure times, Empirical analysis used interval failure time for the prediction of this model. Model selection using the mean square error was presented for effective comparison.

• The Korean Journal of Applied Statistics
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• v.13 no.1
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• pp.11-18
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• 2000

대학의 학업성취도를 나타내는 평점평균은 많은 요인의 영향을 받는 것으로 알려져 있다. 본 논문은 형행입시제도하에서 획득 가능한 요인과 평점평균과의 관련성을 일반 화선형모형(GLM)을 이용하여 통계적으로 분석·평가하고자 한다. 여기서 얻어진 경과는 요즈음 변화가 모색되고 있는 입시제도나 대학교육제도의 개선에 적으나마 도움이 되는 기초자료를 제공할 수 있으리라 믿어진다. 분석자료는 1996, 97학년도 인제대학교에 입학한 학생들의 입시자료와 96,97학년도의 평점평균, 기숙사입사 여부 등을 대상으로 삼았다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.53-60
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• 2014

Redundant handovers cause degraded quality of service to passengers in vehicle. This paper proposes a handover scheme suitable for users traveling in vehicles, which enables continuous learning of the handover process using a discrete-time Markov chain (DTMC). Through AdaBoost machine learning algorithm, the proposed handover scheme avoids unnecessary handover trials when a short dwell time in a target cell is expected or when the target cell is an intermediate cell through which the vehicle quickly passes. Simulation results show that the proposed scheme reduces the number of handover occurrences and maintains adequate throughput.

• 전자공학회논문지 IE
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• v.43 no.1
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• pp.59-66
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• 2006

In this study, we have proposed a motion equation to control synchro drive mobile robot, a path plan to compute and track the best path to given destination and a technique utilizing uniform distribution and cluster management based Monte Carlo localization to have track current position of moving robot. In the localization test which was repeated 73 times resulted as following. The average process time of original Monte Carlo localization was 12.8ms. The proposed cluster management Monte Carlo localization resulted 9.3ms. Also the proposed method resulted correctly in the cases where original method failed.

• Fire Science and Engineering
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• v.11 no.1
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• pp.37-45
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• 1997

The surveying method for determine moveable fuel load estimates is presented. Two types of offices, open plan design and compartmented layout were surveyed and Data are presented for fuel load densities in ten office buildings. Office building fuel load in Korea range from 36kg/$m^2$ to 52kg/$m^2$ with 95% confidence level and represented mean 44.27kg/$m^2$. The results of the study presented the impact of the office layout and computer accessary contribution on the fuel load. In addition, a comparison of fuel load that found at this survey and that found at Fire Protection Dept., University of Maryland, U. S. A was made.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.189-196
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• 2007

In this paper, we proposed a mobile ad hoc routing protocol based on AODV(Ad hoc On demand Distance Vector) with QoS(Quality of Service) support and evaluated the performance through simulation. The waste of communication resources is reduced by establishing the shortest route suitable to QoS support, considering in advance the usable communication resources at each node. For performance evaluation, we analyzed the average data reception rate, considering the node mobility and the number of best effort/QoS data flows. We found that in the mobile Ad Hoc networks the QoS service for some specific data flows increased the average data reception rate for the QoS data flows.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.5
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• pp.584-594
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• 1999

이 논문에서는 CDMA(Code Division Multiple Access)셀룰러 시스템에서 우선순위 큐(Queue)에 기반을 둔 핸드오프채널할당기법의 모델을 제안하였다. 또한 제안한 모델의 성능을 컴퓨터 시뮬레이션을 통해 비우선순위기법 및 FIFO(First In First Out)큐기법과 비교하였다. 제안하는 모델의 핸드오프 채널할당 기법에서는 이동국의 진행방향에 있는 인접 셀(Neighbor Cell)의 파일롯 중에서 임계치가 T-ADD 이상인 파일롯이 있을 경우 기지국이 이 파일롯(Pilot)에 대한 파일롯 세기 측정메시지를 이동국으로부터 수신 한 지점에서 드롭타이머가 종료된후 현재의 셀에서 사용중인 파일롯에 대한 파일롯 세기 측정 메시지를 이동국으로부터 수신한 시점까지 핸드오프 처리가능 영역으로 정의하고 이를 우선순위 큐의 최대큐 대기시간으로 사용하였다. 제안된 기법의 성능을 분석하기 위한 성능평가 척도는 강조종료확률, 호 블록킹 확률, 전체 제공 트래픽에 대한 수행 트래픽 비율, 평균 규크기미치 핸드오프 시 평균 지연시간이다. 성능시뮬레이션결과, 제안된 기법이 전체 시스템 호처리 용량면에서 약간의 단점은 발생하지만 핸드오프 처리에 있어서 높은 성능을 유지함을 알수 있었다.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.211-219
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• 2015

Generalized linear mixed models are used to analyze longitudinal categorical data. Random effects specify the serial dependence of repeated outcomes in these models; however, the estimation of a random effects covariance matrix is challenging because of many parameters in the matrix and the estimated covariance matrix should satisfy positive definiteness. Several approaches to model the random effects covariance matrix are proposed to overcome these restrictions: modified Cholesky decomposition, moving average Cholesky decomposition, and partial autocorrelation approaches. We review several approaches and present potential future work.