• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.69-77
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• 2015

MANET is composed of only the mobile nodes have a limited transmission range. The dynamic topology by the frequent movement of nodes makes routing difficult and is also cause exposed to security vulnerabilities. In this paper, we propose the security routing technique consisted of mechanism of two steps in order to respond effectively to attack by the modification of the routing information and transmit secure data. The hierarchical structure is used and the authentication node that issues the key of the nodes within each cluster is elected in this proposed method. The authentication node manages key issues and issued information for encrypting the routing information from the source node. The reliability value for each node is managed to routing trust table in order to secure data transmission. In the first step, the route discovery is performed using this after the routing information is encrypted using the key issued by the authentication node. In the second step, the average reliability value of the node in the found path is calculated. And the safety of the data transmission is improved after the average reliability value selects the highest path. The improved performance of the proposed method in this paper was confirmed through comparative experiments with CBSR and SEER. It was confirmed a better performance in the transmission delay, the amount of the control packet, and the packet transmission success ratio.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1625-1630
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• 2016

Prostate cancer is the secondary most frequently diagnosed cancer in the world. Although numerous prospective randomized trial have been conducted to guide the management of patients with localized or locally advanced prostate cancer, few clinical trials targeting node-positive prostate cancer have been reported. Therefore, there are still controversies in the optimal management of node-positive prostate cancer. Recently, efficacy of multimodality treatment, including radiation therapy (RT), for such patients has been reported in several articles. The results indicate potential benefit of RT both in adjuvant therapy after prostatectomy and in definitive therapy for node-positive prostate cancer. The aim in this article was to summarize the current evidence for RT and evaluate the role in multimodality treatment for patients with node-positive prostate cancer.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.2
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• pp.7-14
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• 2016

In this paper presents a low power algorithm using a feasible cluster generation method considered glitch. The proposed algorithm is a method for reducing power consumption of a given circuit. The algorithm consists of a feasible cluster generation process and glitches removal process. So that glitches are not generated for the node to which the switching operation occurs most frequently in order to reduce the power consumption is a method for generating a feasible cluster. A feasible cluster generation process consisted of a node value set, dividing the node, the node aligned with the feasible cluster generation. A feasible cluster generation procedure is produced from the highest number of nodes in the output. When exceeding the number of OR-terms of the inputs of the selected node CLB prevents the signal path is varied by the evenly divided. If there are nodes with the same number of outputs selected by the first highest number of nodes in the input produces a feasible cluster. Glitch removal process removes glitches through the path balancing in the same manner as [5]. Experimental results were compared with the proposed algorithm [5]. Number of blocks has been increased by 5%, the power consumption was reduced by 3%.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.4
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• pp.9-17
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• 2020

When IoT sensor nodes are deployed in areas where data collection is challenging, sensors must be relocated if sensing holes occur due to improper placement of sensors or energy depletion, and data collection is impossible. The sensing hole's cluster header transmits a request message for sensor relocation to an adjacent cluster header through a specific relay node. However, since a specific relay node is frequently used, a member sensor located in a specific cluster area adjacent to the sensing hole can continuously receive the movement message. In this paper, we propose a method that avoids the situation in which the sensing hole cluster header monopolizes a specific relay node and allows the cluster header to use multiple relay nodes fairly. Unlike the existing method in which the relay node immediately responds to the request of the header, the method proposed in this paper solves a ping-pong problem and a problem that the request message is concentrated on a specific relay node by applying a method of responding to the request of the header using a timer. OMNeT++ simulator was used to analyze the performance of the proposed method.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.4
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• pp.77-83
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• 2022

As users' needs for customized services increase, the service provision method is changing from a vertical structural service provision method to a horizontal structural service provision method. This paradigm shift has led to a change from the way existing users find the content they want to find and provide customized needs of users by content providers. With the recent development of smartphones and various AI technologies, demand for providing seamless services such as smartphones is increasing in automobiles. However, it is difficult to provide services in line with changes in this service paradigm because automobile services provide services centered on finished car manufacturers rather than individually providing services tailored to user needs. In this paper, we develop a Node-RED-based dynamic vehicle service simulation tool so that users can use the service they want in cars. The simulation tool developed provides a simulation environment for services authored by the user using NodeRed by writing, registering, and using NodeRed.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.4
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• pp.1-16
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• 1997

The cell loss probability recommended in the B-ISDN is in the range $10^{-8}~10^{-12}$. When a simulation technique is used to analyze the performance of the ATM node, an enormous amount of computer processing time is required. In this study, we derive an importance sampling simulation technique that can be used to evaluate the performance of the ATM node very quickly, that is, the probability that the queue size at the ATM node reaches some large value N. The simulation results show that the backlog probability obtianed by the importance saimpling simulation is very close to that obtained by the ordinary simulation and the computer time can be reduced drastically by the importance sampling simulation.

• Korean Management Science Review
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• v.24 no.1
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• pp.25-34
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• 2007

In this study, we consider stationary waiting times in finite-buffer 3-node single-server queues in series with a Poisson arrival process and with either constant or non-overlapping service times. We assume that each node has a finite buffer except for the first node. The explicit expressions of waiting times in all areas of the stochastic system were driven as functions of finite buffer capacities. These explicit forms show that a system sojourn time does not depend on the finite buffer sizes, and also allow one to compute and compare characteristics of stationary waiting times at all areas under two blocking rules communication and manufacturing blocking. The goal of this study is to apply these results to an optimization problem which determines the smallest buffer capacities satisfying predetermined probabilistic constraints on stationary waiting times at all nodes. Numerical examples are also provided.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.245-248
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• 2008

Everytime a node moves out of its area, the connection to the node encounters a handover which may cause much latency. NetLMM(Network based Localized Mobility Management) supports the mobility management for such nodes and improves handover latency using MIH(Media Independent Handover) function. In this paper, we add some messages to NetLMM procedure to improve handover latency and analyze its effects through a scenario based approach

• International Journal of Reliability and Applications
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• v.9 no.1
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• pp.1-5
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• 2008

A heuristic algorithm for reliability optimization of a distributed network system is developed so that the reliability of a large system can be determined efficiently. This heuristic bases on the determination of maximal reliability set of maximum node capacity, maximal link reliability and maximal node degree.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1481-1501
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• 2019

In opportunistic network, the behavior of a node is autonomous and has social attributes such as selfishness.If a node wants to forward information to another node, it is bound to be limited by the node's own resources such as cache, power, and energy.Therefore, in the process of communication, some nodes do not help to forward information of other nodes because of their selfish behavior. This will lead to the inability to complete cooperation, greatly reduce the success rate of message transmission, increase network delay, and affect the overall network performance. This article proposes a hybrid incentive mechanism (Mim) based on the Reputation mechanism and the Credit mechanism.The selfishness model, energy model (The energy in the article exists in the form of electricity) and transaction model constitute our Mim mechanism. The Mim classifies the selfishness of nodes and constantly pay attention to changes in node energy, and manage the wealth of both sides of the node by introducing the Central Money Management Center. By calculating the selfishness of the node, the currency trading model is used to differentiate pricing of the node's services. Simulation results show that by using the Mim, the information delivery rate in the network and the fairness of node transactions are improved. At the same time, it also greatly increases the average life of the network.