• 한국컴퓨터정보학회논문지
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• 제25권11호
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• pp.105-114
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• 2020

본 논문에서는 산업 애플리케이션을 위한 5G Non-Public Network에서의 보안 이슈를 다룬다. 일반 대중에게 모바일 네트워크 서비스를 제공하는 공공 네트워크와는 달리, 5G Non-Public Network는 명확하게 정의된 사용자 조직이나 조직들의 그룹에게 5G 네트워크 서비스를 제공하며, 캠퍼스나 공장과 같이 사용자 조직이 지정한 영역 내에 구축된다. 본 논문의 주목적은 5G-ACIA (5G Alliance for Connected Industries and Automation)에서 제안한 네 가지 구축 모델에 따라 5G Non-Public Network가 이산 산업 및 공정 산업을 위하여 구축될 경우 고려되어야 할 보안 위협 및 잠재적 보안 요구사항을 도출하는 것이다. 본 논문의 범위를 명확하게 하기 위해 먼저 5G Non-Public Network에 적용할 보안 툴박스를 심층 방어 개념으로 표현한다. 일반적인 5G 이동통신 서비스와 관련된 보안 이슈는 본 논문의 범위에 포함되지 않는다. 그 다음, 산업 도메인에 5G-ACIA의 구축 모델을 적용할 때 고려해야 할 보안 이슈를 도출한다. 도출된 보안 이슈들은 세 가지 범주로 나뉘며 각각의 보안 이슈들은 개요, 보안 위협 및 잠재적 보안 요구사항의 순서로 서술된다.

• 스마트미디어저널
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• 제13권3호
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• pp.45-52
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• 2024

오늘날 점점 증가하는 위협 환경에서는 보안 이벤트에 대한 신속하고 효과적인 탐지 및 대응이 필수적이다. 이러한 문제를 해결하기 위해 많은 기업과 조직에서는 다양한 보안관제시스템을 도입하여 보안 위협에 대응하고 있다. 그러나 기존 보안관제시스템은 보안 이벤트의 복잡성과 다양한 특성으로 인해 어려움을 겪고 있다. 본 연구에서는 인공지능 기반의 자동화된 통합보안관제시스템 모델을 제안하였다. 인공지능 기술인 딥러닝을 기반으로 하여 다양한 보안 이벤트에 대해 효과적인 탐지와 이를 처리하는 기능들을 제공한다. 이를 위해 모델은 기존의 보안관제시스템 한계를 극복하기 위하여 다양한 인공지능 알고리즘과 머신러닝 방법을 적용한다. 제안된 모델은 운영자의 업무량을 줄이고 효율적인 운영을 보장하며 보안 위협에 대한 신속한 대응을 지원하게 될 것이다.

• ETRI Journal
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• 제30권1호
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• pp.81-88
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• 2008

The security threat posed by worms has steadily increased in recent years. This paper discusses the application of the optimal and sub-optimal Internet worm control via Pontryagin's maximum principle. To this end, a control variable representing the optimal treatment strategy for infectious hosts is introduced into the two-factor worm model. The numerical optimal control laws are implemented by the multiple shooting method and the sub-optimal solution is computed using genetic algorithms. Simulation results demonstrate the effectiveness of the proposed optimal and sub-optimal strategies. It also provides a theoretical interpretation of the practical experience that the maximum implementation of treatment in the early stage is critically important in controlling outbreaks of Internet worms. Furthermore, our results show that the proposed sub-optimal control can lead to performance close to the optimal control, but with much simpler strategies for long periods of time in practical use.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.106-113
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• 2014

Rotor eccentricity is one of the major factors that directly influence the security of horizontal electrical machines, and the critical speed of the shaft has a close relationship with vibration. This paper deals with the influence of thermal expansion on the rotor eccentricity and critical speed in large dry submersible motors. The dynamic eccentricity (where the rotor is still turning around the stator bore centre but not its own centre) and critical speed of a three-phase squirrel-cage submersible induction motor are calculated via hybrid analytical/finite element method. Then the influence of thermal expansion is investigated by simulation. It is predicted from the study that the thermal expansion of the rotor and stator gives rise to a significant air-gap length decrement and an inconspicuous slower critical speed. The results show that the thermal expansion should be considered as an impact factor when designing the air gap length.

• Journal of Information Processing Systems
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• 제15권1호
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• pp.189-202
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• 2019

During thermal power coal-fired boiler operation, it is very important to detect the pulverized coal concentration in the air pipeline for the boiler combustion stability and economic security. Because the current measurement methods used by power plants are often involved with large measurement errors and unable to monitor the pulverized coal concentration in real-time, a new method is needed. In this paper, a new method based on microwave circular waveguide is presented. High Frequency Electromagnetic Simulation (HFSS) software was used to construct a simulation model for measuring pulverized coal concentration in power plant pipeline. Theoretical analysis and simulation experiments were done to find the effective microwave emission frequency, installation angle, the type of antenna probe, antenna installation distance and other important parameters. Finally, field experiment in Jilin Thermal Power Plant proved that with selected parameters, the measuring device accurately reflected the changes in the concentration of pulverized coal.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권6호
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• pp.597-611
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• 2009

With the advent of ubiquitous computing society, many advanced technologies have enabled wireless sensor networks which consist of small sensor nodes. However, the sensor nodes have limited computing resources such as small size memory, low battery life, short transmission range, and low computational capabilities. Thus, decreasing energy consumption is one of the most significant issues in wireless sensor networks. In addition, numerous applications for wireless sensor networks are recently spreading to various fields (health-care, surveillance, location tracking, unmanned monitoring, nuclear reactor control, crop harvesting control, u-city, building automation etc.). For many of them, supporting security functionalities is an indispensable feature. Especially in case wireless sensor networks should provide a sufficient variety of security functions, sensor nodes are required to have more powerful performance and more energy demanding features. In other words, simultaneously providing security features and saving energy faces a trade-off problem. This paper presents a novel energy-efficient security architecture in an IEEE 802.15.4-based wireless sensor network called the Hybrid Adaptive Security (HAS) framework in order to resolve the trade off issue between security and energy. Moreover, we present a performance analysis based on the experimental results and a real implementation model in order to verify the proposed approach.

• Journal of Power Electronics
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• 제18권1호
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• pp.289-299
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• 2018

Electric-field coupled power transfer (ECPT) systems employ a high frequency electric field as an energy medium to transfer power wirelessly. Existing ECPT systems have made great progress in terms of increasing the transfer distance. However, the topologies of these systems are complex, and the transfer characteristics are very sensitive to variations in the circuit parameters. This paper proposes an ECPT system with a double-sided LC network, which employs a parallel LC network on the primary side and a series LC network on the secondary side. With the same transfer distance and output power, the proposed system is simpler and less sensitive than existing systems. The expression of the optimal driving voltage for the coupling structure and the characteristics of the LC networks are also analyzed, including the transfer efficiency, parameter sensitivity and total harmonic distortion. Then, a design method for the system parameters is provided according to these characteristics. Simulations and experiments have been carried out to verify the system properties and the design method.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.948-958
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• 2022

Since reliability and security of man-machine system increasingly depend on reliability of human, human reliability analysis (HRA) has attracted a lot of attention in many fields especially in nuclear engineering. Dependence assessment among human tasks is a important part in HRA which contributes to an appropriate evaluation result. Most of methods in HRA are based on experts' opinions which are subjective and uncertain. Also, the dependence influencing factors are usually considered to be constant, which is unrealistic. In this paper, a new model based on Dempster-Shafer evidence theory (DSET) and fuzzy number is proposed to handle the dependence between two tasks in HRA under uncertain and dynamic situations. First, the dependence influencing factors are identified and the judgments on the factors are represented as basic belief assignments (BBAs). Second, the BBAs of the factors that varying with time are reconstructed based on the correction BBA derived from time value. Then, BBAs of all factors are combined to gain the fused BBA. Finally, conditional human error probability (CHEP) is derived based on the fused BBA. The proposed method can deal with uncertainties in the judgments and dynamics of the dependence influencing factors. A case study is illustrated to show the effectiveness and the flexibility of the proposed method.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.800-803
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• 2003

최근 인터넷 사용자가 급증하면서 침해 사고 역시 크게 증가되고 있다. 이에 해킹과 침입으로부터 시스템과 네트워크를 보호하기 위해 정보보호 제품이 개발되고 있으나, 해킹 기법과 바이러스들도 점차 자동화, 지능화, 분산화, 대규모화, 은닉화 되어 가고 있다. 따라서, 이러한 위협에 대처하기 위해 종합적인 네트워크 보안 서비스가 필요하다. 본 논문에서는 역추적, 복구, 네트워크 취약성 분석, 공격 예측 등의 새로운 네트워크 보안서비스들과 이를 위한 고려사항들에 대해서 고찰한다.

• Journal of information and communication convergence engineering
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• 제10권4호
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• pp.343-348
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• 2012

ZigBee Network is enabling technology for home automation, surveillance and monitoring system. For better secure network environment, secure and robust security model is important. The paper proposes an application, attribute-based proxy re-encryption on ZigBee networks. The method can distribute the authority to designated sensor nodes to decrypt re-encrypted ciphertext with associated attributes. However, a previous method is required to compute complex pairing operations. The high complexity is not suited to low resource device sensor networks, and it does not provide routing security either. To resolve these problems, we present a novel mechanism. The method can reduce overhead by imposing overhead to full function devices and ensure routing paths as well.