• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1159-1166
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• 2014

In this paper, a resource management scheme for enhancing the network connectivity and reliability in wireless USB system is proposed. Wireless USB protocol is suitable for the application that supports the real-time multimedia service in Ship Area Network since it supports high speed data transfer. However, the device's mobility is caused the dramatic change of link state and network topology, and is occurred the degradation of network performance. Therefore, a resource management scheme for wireless USB system is proposed in this paper. The proposed technique can intelligently treat the change of link state, and solve the degradation of network performance. The simulation results show that proposed protocol can enhance the throughput and delay performance by selecting relay device with better link state.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.10
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• pp.843-850
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• 2013

Cognitive radio systems have been considered as a strong solution of frequency scarcity due to the limit of frequency resources. This paper proposed an active interference management scheme that the secondary system can coexist with the primary system in the same frequency band without interference. Using the proposed protocol, the secondary user acquires interference channel information and transmit/receive filter information and designs precoding matrix using these information. Since interference from the secondary systems are collected to unused subchannels of the primary system, the primary system can suppress interference without additional process. The secondary systems suppress interference from the primary system using whitening matched filter so that the spectral efficiency can be improved. Numerical results provides that the proposed scheme improves performance of the secondary systems without interference to the primary system and do not degrade performance of the primary system even if the number of the secondary systems increases.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.70-79
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• 2020

The main objective of this research to develop an IoT based wireless contactless ultrasonic system (ICUS) and its application to concrete structure. The developed system consists of 16 mems, 2Mhz digitizer, amplifying circuit, FPGA, and wifi module, enabling to measure leaky surface waves from concrete specimens without physical coupling process and wires. Multi-channel analysis is performed to improve the accuracy of data analysis, and the velocity of leaky surface waves and acoustics are derived. Field inspection of railroad concrete sleepers is conducted to evaluate the performance of the system and to compare the results with conventional ultrasonic pulse velocity (UPV). As a result of the field inspection, UPV was limited to evaluate damages. This is because crack pattern of railroad sleepers is parallel to ultrasonic ray path and accessibility of the railroad at the field is disadvantageous to contact-based UPV. On the other hand, ICUS possibly detect the damages as reduction of dynamic modulus by up to 59% compared to non-damaged specimen.

• Journal of IKEEE
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• v.22 no.4
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• pp.953-958
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• 2018

In this study, a portable detection system was developed that can detect harmful gas and signals simultaneously in an enclosed space of industrial sites and underground facilities. The developed system is a sensor module for gas detection, a patch type 1 channel small ECG sensor, a module for three-axial acceleration detection sensor, and a system for statistics. In order to verify the performance of the system modules, the digital resolution, signal frequency, output voltage, and ultra-small modules were evaluated. As a result of the performance of the developed system, the digital resolution was 300 (rps) and the signal amplification gain was 500 dB or more, and the ECG module was manufactured with $50mm{\times}10mm{\times}10mm$ to increase patch utilization. It is believed that the product of this research will be valuable if it is used as an IoT-based management system for real-time monitoring of industrial workers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.1-7
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• 2019

Recently, multimedia streaming service has been activated, and the demand for high-quality multimedia convergence contents services is predicted to increase significantly in the future. The issues of the increasing network load due to the rise of multimedia streaming traffic must be addressed in order to provide QoS guaranteed services. To do this, an efficient network resource management and mobility support technologies are needed through seamless mobility support for heterogeneous networks. Therefore, in this paper, an MIH technology was used to recognize the network situation information in advance and reduce packet loss due to handover delays, and an ACLMIH-FHPMIPv6 is designed that can provide an intelligent interface through introducing a hierarchical mobility management technique in FPMIPv6 integrated network.

• Journal of the Korean Society for information Management
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• v.37 no.4
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• pp.27-60
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• 2020

Sejong City Library information services and programs proposed in this study are proposed by combining cases of local representative libraries and overseas libraries. As a feature of the proposal, first, various information services that can be provided by the Sejong City Library are proposed by area, by user, by data type, by media, by partner institution, etc. Second, by reinforcing user programs for each life cycle, various reading programs by age and interest, such as reading discussion, reading experience, and reading events, are provided. Reinforce user-based programs that reflect the characteristics of Sejong City's population, such as adult, child, and family programs. Third, secure and utilize maker space space. Fourth, the reading program developed by the Sejong City Library is promoted and shared in cooperation with local libraries. Fifth, induce participation of local residents in Sejong City, volunteer activities and talent donation. Sixth, propose library information services using library websites and social media, and develop channels for mutual cooperation with users.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.1
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• pp.15-28
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• 1999

In Multilevel Secure Database Management System(MLS/DBMS), we assume that system has a security clearance level for each user and a classification level for each data item in system and the objective of these systems is to protect secure information from unauthorized user. Many algorithms which have been researched have focus on removing covert channel by modifying conventional lock-based algorithm or timestamp-based algorithm. but there is high-level starvation problem that high level transaction is aborted by low level transaction repeatedly. In order to solve this problem, we propose an algorithm to reduce high-level starvation using dynamic adjustment of serialization order, which is basically using orange lock. Because our algorithm is based on a single version unlike conventional secure algorithms which are performed on multiversion, it can get high degree of concurrency control. we also show that it guarantees the serializability of concurrent execution, and satisfies secure properties of MLS/DBMS.

• Journal of the Korean Society for information Management
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• v.38 no.2
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• pp.277-303
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• 2021

The purpose of the research is to investigate general citizens' information needs, seeking and uses about both disaster and health information in the middle of disaster of COVID-19 pandemic: what kinds of information they need, what kinds of information sources they use, which channels and media they use to learn the information, etc. To achieve the goal, the study conducted an online survey for general citizens over the age of 20. The survey is composed of 45 questions including four topics-demographic characteristics, information seeking behavior on both disaster and health, and the roles of public information organizations such as libraries in the middle of disaster. On the basis of the results, the research discusses and suggests that what kinds of information should be supplied and in what manners, and which media or information systems should be used when the governments or public organizations provide the information regarding disaster and health, and what roles public information organizations such as libraries should play in the middle of disaster.

• Journal of the Korean Society for information Management
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• v.38 no.2
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• pp.305-336
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• 2021

This study explored the user's information needs and information behavior for the development of academic library services. The content analysis of qualitative data showed that the in-depth interview participants have six types of information needs such as 'suitability, up-to-dateness, uniqueness, reliability, practicality, and convenience' while going through societal, educational, and research-related changes. Interview participants solved their information needs by acquiring the resources necessary for each individual's task through information behaviors using information media, human resources and the places. Each participant tried to solve his/her information problem through individual efforts based on their different media and information utilization capabilities. Based on the analysis, this study presented four directions in the development of academic library services. They are an personalized information literacy service, a space to meet the characteristics of information needs, an infrastructure platform for exchanging human resources, and an accessible support service for utilizing information media.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.70-77
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• 2022

This paper proposes database generation and management system for small-pixelized airborne target recognition. The proposed system has five main features: 1) image extraction from in-flight test video frames, 2) automatic image archiving, 3) image data labeling and Meta data annotation, 4) virtual image data generation based on color channel convert conversion and seamless cloning and 5) HOG/LBP-based tiny-pixelized target augmented image data. The proposed framework is Python-based PyQt5 and has an interface that includes OpenCV. Using video files collected from flight tests, an image dataset for airborne target recognition on generates by using the proposed system and system input.