• The Journal of the Acoustical Society of Korea
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• v.13 no.4
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• pp.5-11
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• 1994

In this paper, the ciassification of Korean character type using multi neural network and fuzzy inference based on block partition is studied. For the effective classification of a consonant and a vowel, block partition method which devide the region of a consonant and a vowel for each type in the character is proposed. And the partitioned block can be changed according to the each type adaptively. For the improvement of classification rate, the multi neural network with a whole and a part neural network is consisted, and the character type by using fuzzy inference is decided. To verify the validity of the proposed method, computer simulation is accomplished, and from the classification rate $92.6\%$, the effectivity of the method is confirmed.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.434-442
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• 2018

Recently, the threat to the security and damage of important data leaked by devices of intranet infected by malicious code through the Internet have been increasing. Therefore, the partitioned intranet model that blocks access to the server for business use by implementing authentication of devices connected to the intranet is required. For this, logical net partition with the VDI(Virtual Desktop Infrastructure) method is no information exchange between physical devices connected to the intranet and the virtual device so that it could prevent data leakage and improve security but it is vulnerable to the attack to expose internal data, which has access to the server for business connecting a nonregistered device into the intranet. In order to protect the server for business, we suggest a blockchain based network partition model applying blockchain technology to VDI. It contributes to decrease in threat to expose internal data by improving not only capability to verify forgery of devices, which is the vulnerability of the VDI based logical net partition, but also the integrity of the devices.

• International journal of advanced smart convergence
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• v.12 no.1
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• pp.1-8
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• 2023

Smart IoT over high speed network and high performance smart devices explodes the ubiquitous services and applications. Nearest Neighbor(NN) query is one of the important type of queries that have to be supported for ubiquitous information services. In order to process efficiently NN queries in the wireless broadcast environment, it is important that the clients determine quickly the search space and filter out NN from the candidates containing the search space. In this paper, we propose a hybrid index of Voronoi and grid partition to provide quick search space decision and rapid filtering out NN from the candidates. Grid partition plays the role of helping quick search space decision and Voronoi partition providing the rapid filtering. We show the effectiveness of the proposed index by comparing the existing indexing schemes in the access time and tuning time. The evaluation shows the proposed index scheme makes the two performance parameters improved than the existing schemes.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.373-375
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• 2000

By DC load flow approximation, we analyzed marginal cost that is the important factor of price signal for network congestion management and expressed as a function of load. In network congestion, a large scale electric network is partitioned into subnetwork to provide a effetive price signal through zonal pricing. We propose a new network partition technique using marginal cost sensitivity with a variety of load consumption.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.4
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• pp.299-304
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• 2017

A wireless passive sensor network is a network consisting of sink nodes, sensor nodes, and radio frequency (RF) sources, where an RF source transfers energy to sensor nodes by radiating RF waves, and a sensor node transmits data by consuming the received energy. Against theoretical expectations, a wireless passive sensor network suffers from many practical difficulties: scarcity of energy, non-simultaneity of energy reception and data transmission, and inefficiency in allocating time resources. Perceiving such difficulties, we propose a simple contending-type medium access control (MAC) scheme for many sensor nodes to deliver packets to a sink node. Then, we derive an approximate expression for the network-wide throughput attained by the proposed MAC scheme. Also, we present an approximate expression for the optimal partition, which maximizes the saturated network-wide throughput. Numerical examples confirm that each of the approximate expressions yields a highly precise value for network-wide throughput and finds an exactly optimal partition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4703-4723
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• 2018

In recent years, dense small cell network has been deployed to address the challenge that has resulted from the unprecendented growth of mobile data traffic and users. It has proven to be a cost efficeient solution to offload traffic from macro-cells. Software defined heterogeneous wireless network can decouple the control plane from the data plane. The control signal goes through the macro-cell while the data traffic can be offloaded by small cells. In this paper, we propose a framework for cell virtualization and user association in order to satisfy versatile requirements of multiple tenants. In the proposed framework, we propose an interference graph partioning based virtual-cell association and customized physical-cell association for multi-homed users in a software defined small cell network. The proposed user association scheme includes 3 steps: initialization, virtual-cell association and physical-cell association. Simulation results show that the proposed virtual-cell association outperforms the other schemes. For physical-cell association, the results on resource utilization and user fairness are examined for mobile users and infrastructure providers.

• Journal of Communications and Networks
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• v.17 no.3
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• pp.286-295
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• 2015

Avionic databuses fulfill a critical function in the connection and communication of aircraft components and functions such as flight-control, navigation, and monitoring. Ethernet-based avionic databuses have become the mainstream for large aircraft owning to their advantages of full-duplex communication with high bandwidth, low latency, low packet-loss, and low cost. As a new generation aviation network communication standard, avionics full-duplex switched ethernet (AFDX) adopted concepts from the telecom standard, asynchronous transfer mode (ATM). In this technology, the switches are the key devices influencing the overall performance. This paper reviews the avionic databus with emphasis on the switch architecture classifications. Based on a comparison, analysis, and discussion of the different switch architectures, we propose a new avionic switch design based on a time-division switch fabric for high flexibility and scalability. This also merges the design concept of space-partition switch fabric to achieve reliability and predictability. The new switch architecture, called space partitioned shared memory switch (SPSMS), isolates the memory space for each output port. This can reduce the competition for resources and avoid conflicts, decrease the packet forwarding latency through the switch, and reduce the packet loss rate. A simulation of the architecture with optimized network engineering tools (OPNET) confirms the efficiency and significant performance improvement over a classic shared memory switch, in terms of overall packet latency, queuing delay, and queue size.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.141-147
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• 2009

To initialize and maintain self-organizing networks such as mobile ad hoc networks, address allocation protocol is essentially required. However, centralized approaches that pervasively used in traditional networks are not recommended in this kind of networks since they cannot handle with mobility efficiently. In addition, previous distributed approaches suffer from inefficiency with control overhead caused by duplicated address detection and management of available address pool. In this paper, we propose a new dynamic address allocation scheme, which is based on adaptive partition. An available address is managed in distributed way by multiple agents and partitioned adaptively according to current network environments. Finally, simulation results reveal that a proposed scheme is superior to previous approach in term of address acquisition delay under diverse simulation scenarios.

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.128-131
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• 1985

A series of copolymer membranes of 2-hydroxyethylmethacrylate (HEMA) with selected hydrophobic monomers were prepared without crosslinking agents. The equilibrium water content, the partition coefficient, and the permeability of the solutes such as urea, methylurea, 1,3-di-methylurea, and acetamide via these membranes were measured. The partition coefficient data show that as the hydrophobicity of solutes increased, the partition of solutes were dictated by hydrophobic interaction between solute and polymer matrix. Diffusion coefficients obtained in these experiments decrease as the water content of polymer membrane decreases. This decrease is blunt as the excess heat capacities, ${\phi}C^0_p$ (excess) in aqueous solution at infinite dilution of solute increases. To investigate the relationship between water content and diffusion coefficient, the results of the diffusion experiments were examined in light of a free-volume model of diffusive transport. The remarkable increase of urea mobility in the polymer network containing relatively larger bulk water can be considered as water structure breaking effect.

• Journal of Information Processing Systems
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• v.10 no.4
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• pp.568-580
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• 2014

To enhance the utilization of the traffic channels of a network (instead of allocating radio channel to an individual user), a channel or a group of channels are allocated to a user group. The idea behind this is the statistical distribution of traffic arrival rates and the service time for an individual user or a group of users. In this paper, we derive the blocking probability and throughput of a subscriber station of Worldwide Interoperability for Microwave Access (WiMAX) by considering both the connection level and packet-level traffic under a complete partition scheme. The main contribution of the paper is to incorporate the traffic shaping scheme onto the incoming turbulent traffic. Hence, we have also analyzed the impact of the drain rate of the buffer on the blocking probability and throughput.