• Convergence Security Journal
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• v.11 no.5
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• pp.13-19
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• 2011

Mobile nodes in MANETs have the nature of unrestricted mobility so that they will join and leave the network frequently. Therefore, it important consideration to determine the optimal distance progress between relaying nodes along the route in order to maintain the established route for an arbitrary length of time (i.e., route duration). In this paper, we derived the link maintenance probability by considering the initial distance between two relaying nodes and node mobility. Based on the link maintenance probability, we further analyzed the route stability by considering the impact of distance progress between relaying nodes along the route.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.645-654
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• 2021

This research aims to examine the influence of road transportation infrastructure on the mobility of goods transport and the regional economy in Langkat Regency in Indonesia. This type of research is an associative and explanatory research whose data is obtained through a questionnaire survey. This study took a sample of 305 respondents using probability sampling in Langkat Regency, North Sumatera, Indonesia. Data analysis techniques use path analysis. The research results showed that the road transportation infrastructure variables had a significant and positive effect on the mobility of goods transport. Road transportation infrastructure and freight mobility simultaneously have a significant and positive effect on the economy of Langkat Regency. Road transportation infrastructure with the dimensions of road accessibility and maintenance partially directly has a significant and positive effect on the economy of the Langkat Regency. Road transportation infrastructure with the dimensions of road design and road construction quality partially does not have a direct effect on the regional economy, but has a positive and significant effect through the mobility of freight transport. The mobility of goods transport becomes an intervening variable that acts to mediate or determine the relationship between road transportation infrastructure variables to the regional economy.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.347-352
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• 2017

In this paper, we propose a method that reduces mobile user's handover call dropping probability by using cognitive radio technology(CR) in cellular - based wireless cognitive radio networks. The proposed method predicts a cell to visit by Ziv-Lempel algorithm, and then supports mobile user with prediction of spectrum holes based on CR technology when allocated channels are short in the cell. We make neural network predict spectrum hole resources, and make handover calls use the resources before initial calls. Simulation results show CR technology has the capability to reduce mobile user handover call dropping probability in cellular mobile communication networks.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.71-83
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• 2009

In this paper, we propose a paging scheme considering local environment and moving patterns of mobile hosts on HMIPv6. The proposed paging scheme can adaptively construct a paging domain according to handoff probability of mobile hosts and local environment, and process a paging based on handoff probability stage by stage. For analysis of the proposed paging scheme, we simulate our scheme in two different experiment environments: an open environment like a square and a restricted environment like downtown. In experiment results, the proposed scheme shows superior performance to that of compared scheme all over. Particularly, in case of high call request rate and a restricted environment, the proposed scheme shows better performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.545-548
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• 2001

3GPP2 방식에서는 Macro Mobility 지원을 위하여 MIP를 이용하며 PDSN은 FA의 기능을 수행한다. PDSN 관리 영역 내의 하나의 RN에서 다른 RN으로 이동시에 지원되는 이동성을 Micro Mobility라 한다. Micro Mobility에서 Seamless한 핸드오프를 위해 RN간에 멀티캐스트 그룹 메커니즘을 이용할 경우, 핸드오프 예상시간에 따라 등급별로 버퍼를 다르게 할당하여 멀티캐스트 하는 방법과 단순 멀티캐스트 하는 방법이 있다. 본 논문은 Micro Mobility를 지원하기 위한 멀티캐스트 그룹 메커니즘 기반의 Seamless 핸드오프 알고리즘에서 등급별로 버퍼를 다르게 할당할 경우와 단순 멀티캐스트 할 경우의 블록킹 확률을 비교 분석한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.11-21
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• 2015

In order to achieve success in ground operations, searching for moving targets is one of critical factors. Usually, the system of searching for adversary ground moving targets has complex properties which includes target's moving characteristics, camouflage level, terrain, weather, available search time window, distance between target and searcher, moving speed, target's tactics, etc. The purpose of this paper is to present a practical quantitative method for effectively searching for infiltrated moving targets considering aforementioned complex properties. Based upon search theories, this paper consists of two parts. One is infiltration route analysis, through terrain and mobility analysis. The other is building dynamic probability maps through Monte Carlo simulation to determine the prioritized searching area for moving targets. This study primarily considers ground moving targets' moving pattern. These move by foot and because terrain has a great effect on the target's movement, they generally travel along a constrained path. With the ideas based on the terrain's effect, this study deliberately performed terrain and mobility analysis and built a constrained path. In addition, dynamic probability maps taking terrain condition and a target's moving speed into consideration is proposed. This analysis is considerably distinct from other existing studies using supposed transition probability for searching moving targets. A case study is performed to validate the effectiveness and usefulness of our methodology. Also, this study suggests that the proposed approach can be used for searching for infiltrated ground moving target within critical time window. The proposed method could be used not only to assist a searcher's mission planning, but also to support the tactical commander's timely decision making ability and ensure the operations' success.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.1-14
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• 2002

The most important issue in providing multimedia traffic on a mobile computing environments is to guarantee the mobile host(client) with consistent QoS(Quality of Service). However, the QoS negotiated between the client and network in one cell may not be honored due to client mobility, causing hand-offs between cells. In this paper, a call admission control mechanism is proposed to provide consistent QoS guarantees for multimedia traffics in a mobile computing environment. Each cell can reserve fractional bandwidths for hand-off calls to its adjacent cells. It is important to determine the right amount of reserved bandwidth for hand-off calls because the blocking probability of new calls may increase if the amount of reserved bandwidth is more than necessary. An adaptive bandwidth reservation based on an MPP(Mobility Pattern Profile) and a 2-tier cell structure has been proposed to determine the amount of bandwidth to be reserved in the cell and to control dynamically its amount based on its network condition. We also propose a call admission control based on this bandwidth reservation and "next-cell prediction" scheme using an MPP. In order to evaluate the performance of our call admission control mechanism, we measure the metrics such as the blocking probability of our call admission control mechanism, we measure the metrics such as the blocking probability of new calls, dropping probability of hand-off calls, and bandwidth utilization. The simulation results show that the performance of our mechanism is superior to that of the existing mechanisms such as NR-CAT1, FR-CAT1, and AR-CAT1.

• Journal of the military operations research society of Korea
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• v.6 no.1
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• pp.103-117
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• 1980

Stochastic duels have been studied by Ancker, William, Bhashyam, Gafarian, Jaiswal, Singh, and others, Stochastic duels are classified in terms of factors such as kill probability, ammunition, time duration, surprise, mobility, time of flight, etc. The purpose of this paper is to summarize and analyze the models of stochastic duels that have been studied so far, and to study the effect of the factors to the win probability.

• Journal of Information Processing Systems
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• v.2 no.1
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• pp.34-38
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• 2006

In the wireless network, TCP performs poorly because it was originally designed for wired networks and does not take into consideration wireless characteristics such as mobility, high-loss probability, and hidden-terminal problems. In particular, in the wireless multi-hop networks, a large congestion window increases the probability of contention and packet losses, and TCP performance is degraded severely as a result. So, it is necessary to limit the TCP congestion window size in order keep the probability of contention loss in the system to a minimum. In this paper, we propose a new scheme for determining the maximum congestion window size based on the measured bandwidth and Round-Trip-Time (RTT). Using ns-2 simulation, we show that the proposed scheme reduces the probability of packet contention and improves TCP performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1034-1051
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• 2016

Mobility models are invaluable for determining the performance of routing protocols in opportunistic networks. The movement of nodes has a significant influence on the topological structure and data transmission in networks. In this paper, we propose a new mobility model called the campus-based community mobility model (CBCNM) that closely reflects the daily life pattern of students on a real campus. Consequent on a discovery that the pause time of nodes in their community follows a power law distribution, instead of a classical exponential distribution, we abstract the semi-Markov model from the movement of the campus nodes and analyze its rationality. Then, using the semi-Markov algorithm to switch the movement of the nodes between communities, we infer the steady-state probability of node distribution at random time points. We verified the proposed CBCNM via numerical simulations and compared all the parameters with real data in several aspects, including the nodes' contact and inter-contact times. The results obtained indicate that the CBCNM is highly adaptive to an actual campus scenario. Further, the model is shown to have better data transmission network performance than conventional models under various routing strategies.