• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.120-124
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• 2023

Strong surface waves among collinearly arranged patch antenna arrays pose unwanted inter element coupling particularly when high permittivity dielectric materials are used. In order to avert those waves, a novel Defected Ground Structure (DGS) is carved out systematically between two E-plane patch antenna elements. The introduced low profile μ shaped structure consequently improves impedance bandwidth and reflection coefficient by suppressing surface waves considerably. Parametric simulation results are analyzed and discussed.

• International Journal of Computer Science & Network Security
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• v.24 no.7
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• pp.118-122
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• 2024

The dielectric material is a basic element which impacts considerably on a microstrip structure performances. This project demonstrates how filter performances such as gain, bandwidth, return loss and insertion loss change proportionally with substrate material variation. The RT/Duroid 5880 and the FR-4 are two dielectric materials proposed as substrates of a low pass microstrip filter. The design and simulation are done on ADS software. The transmission and reflection characteristics show that the RT/ Duroid 5880 as a dielectric substrate permits to obtain better performance as compared to the FR-4 substrate.

• Korean Institute of Interior Design Journal
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• v.19 no.6
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• pp.249-256
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• 2010

For guaranteeing for security of nuclear power plant, ergonomic factors have been applied to design of main control room, core area for management and control of nuclear power plant, but design elements for performance of operators have been ignored. As the behaviors of operators are important for security of nuclear power plant, space design which makes them pleasant psychologically and makes them maintain attention on security equipments ceaselessly is required. Therefore, the purpose of this study is to analyze space characteristics of main control rooms according to regulations of nuclear power plant and general guidelines of space design, and to offer basic data for designing of main control room which makes operators pleasant psychologically and physically. At first, theoretical issues related with design of main control room are reviewed and several premises of space are developed by abstracting design elements from common space and regulations of nuclear power plant and, then integrating each design elements interactively. In short, the improvement of system environment based on human-machine interface space has brought about perceptual, cognitive, and spatial changes and has realized next generation of main control rooms. And, differences and similarities between ordinary space and main control room, which ergonomic sizes and regulations are applied and is VDT environment based on LDP, are discussed in relation to 13 design elements and 17 space premise.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1422-1431
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• 2015

The reliability of power system components can be affected by a numbers of factors such as the health level of components, external environment and operation environment of power systems. These factors also affect the electrical parameters of power system components for example the thermal capacity of a transmission element. The relationship of component reliability and power system is, therefore, a complex nonlinear function related to the above-mentioned factors. Traditional approaches for reliability assessment of power systems do not take the influence of these factors into account. The assessment results could not, therefore, reflect the short-term trend of the system reliability performance considering the influence of the key factors and provide the system dispatchers with enough information to make decent operational decisions. This paper discusses some of these important operational issues from the perspective of power system reliability. The discussions include operational reliability of power systems, reliability influence models for main performance parameters of components, time-varying reliability models of components, and a reliability assessment algorithm for power system operations considering the time-varying characteristic of various parameters. The significance of these discussions and applications of the proposed techniques are illustrated by case study results using the IEEE-RTS.

• Journal of Internet of Things and Convergence
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• v.5 no.2
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• pp.103-110
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• 2019

In this paper, we suggested how the Internet of Things (IoT) technology could be applied to an internet platform that is used for managing the customer's power grid efficiently. For an internet platform with efficient management, analysis is done by several sections; communication method, and its protocol, and also security element. From this analysis, with currently used sensors, we have presented a development method for the sensor to server data reliable communication solution and data management server with a security solution. Moreover, this paper suggests a communication module that could be used for a power grid management platform, protocol and security algorithm and also a way to build a server for managing those systems and modules.

• Computers and Concrete
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• v.19 no.4
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• pp.387-394
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• 2017

To study the effects of water-cement ratio changes and cracks on chloride ion transmission rate in cracked concrete, RCM method was adopted to accelerate the diffusion of chloride ion in cracked concrete, and the changes in chloride ion concentration and around the cracks are inferred by finite-element method. The test results show that as far as prefabricated cracks on concrete components are concerned, the width thresholds of two cracks on the concrete specimens with a water-cement ratio of 0.5 and 0.6 are 0.05 mm and 0.1 mm respectively, the width threshold of two cracks on the concrete specimens with a water-cement ratio of 0.4 is 0.05 mm and 0.2 mm respectively; and the results of numerical simulation show that the smaller the water-cement ratio is, the more significant effects of cracks on chloride ion transmission rate are. As a result, more attention shall be paid to the crack prevention, repairing and strengthening for high-strength concrete.

• Journal of Internet of Things and Convergence
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• v.6 no.3
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• pp.31-37
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• 2020

The cloud computing industry is regarded as a key element of the ICT industry and an important industry that will be a watershed for the future development of ICT industry. Korea has established the 1st~2nd cloud computing development basic plan to induce the growth of the cloud industry. However, the domestic information security guide provides technical vulnerability analysis criteria for Unix and Windows servers, DBMS, network equipment, and security equipment, but fails to provide vulnerability analysis criteria for hypervisors that are key elements of cloud computing. Organizations that have deployed cloud systems will be able to assist in vulnerability analysis using the criteria presented in this paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.592-596
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• 2002

Can speak that DTD is meta data that define meaning of expressed data on XML document. Therefore, In case DTD information is damaged this information to base security of XML document dangerous. Not that attach digital signature on XML document at send-receive process of XML document in this research, proposed method to attach digital signature to DTD. As reading DTD file to end first, do parsing, and store abstracted element or attribute entitys in hash table. Read hash table and achieve message digest if parsing is ended. Compose and create digital signature with individual key after achievement. When sign digital, problem that create entirely other digest cost because do not examine about order that change at message digest process is happened. This solved by method to create DTD's digital signature using DOM that can embody tree structure for standard structure and document.

• Convergence Security Journal
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• v.13 no.6
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• pp.11-16
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• 2013

Mobile node must move optionally and perform the router and the host functions at the same time. These characteristics of nodes have become a potential threatening element of a variety of attacks. In particular, a black hole which malicious node causes packet loss among them is one of the most important issues. In this paper, we propose distributed detection technique using monitoring tables in all node and cooperative detection technique based cluster for an efficient detection of black hole attack. The proposed technique performs by dividing into local detection and cooperative detection process which is composed of process of step 4 in order to improve the accuracy of the attack detection. Cluster head uses a black hole list to cooperative detection. The performance of the proposed technique was evaluated using ns-2 simulator and its excellent performance could be confirmed in the experiment result.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.833-836
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• 2005

Compared to corporation and government networks, home devices and services connected in a home networks has security threats because of the use of various wired and wireless network, middleware and protocol in digital home environment, a restricted system resource of home information appliances and the users who do not care about security. So security is critical element to provide secure services in a home network environments. In this paper we design the access control system based on RBAC to offer secure home network services.