• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.185-191
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• 2015

This paper suggest the safety class communication board in order to design the safety network of the nuclear safety class controller. The reactor protection system use the digitized networks because from analog system to digital system. The communication board shall be provided to pass the required performance and test of the safety class in the digital network used in the nuclear safety class. Communication protocol is composed of physical layer(PHY), data link layer(MAC: Medium Access Control), the application layer in the OSI 7 layer only. The data link layer data package for the cyber security has changed. CRC32 were used for data quality and the using one way communication, not requests and not responses for receiving data, does not affect the nuclear safety system. It has been designed in accordance with requirements, design, verification and procedure for the approving the nuclear safety class. For hardware verification such as electromagnetic test, aging test, inspection, burn-in test, seismic test and environmental test in was performed. FPGA firmware to verify compliance with the life-cycle of IEEE 1074 was performed by the component testing and integration testing.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.249-251
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• 2005

전력 산업구조개편으로 인하여 전력회사의 민영화가 진행됨에 따라 전력회사에서는 한정된 예산으로 배전계통을 운영함으로써 유지보수를 위한 충분한 여유가 없어지게 될 것이다. 이러한 환경에서 한정된 비용으로 계통의 신뢰도를 일정 수준 이상으로 유지해야만 하는 문제에 직면하게 되며, 이는 매우 어려운 일이다. 이를 위해서는 최소의 비용으로 최대의 유지보수 효과를 낼 수 있는 방법을 개발해야 하며, 최적의 유지보수 주기를 찾는 것이 중요한 문제라 할 수 있다. 본 논문에서는 이런 문제론 해결하기 위해, 유지보수 기기 선정 및 유지보수 주기를 결정하는데 있어 검증된 기법인 Reliability Centered Maintenance (RCM) 기법을 이용하였다. 배전계통 기기의 유지보수에 있어서 Four-state Markov 모델을 이용하여 기기의 유지보수에 드는 비용과 기기의 고장에 의한 정전비용 사이의 trade-off를 고려하여 총 비용이 최소가 되는 최적의 유지보수 주기를 찾고자 한다. 이를 위하여 기존의 모델에서 평균고장률(mean failure rate)을 사용한 것과는 달리 시변 고장률(time-varying failure rate)을 적용하였으며, 또한 유지보수에 따른 고장률의 감소도 고려함으로써 최적의 유지보수 주기를 결정할 수 있었다.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.153-158
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• 2007

기존의 모바일 기기들은 일반화된 고정 인터페이스 상태의 제품으로, 사용자가 단순 학습을 통해 반복된 인터렉션과 구성만을 이용하는 수준이었으나 최근과 같이 기기가 지능적이고 다양화되면서 개인의 요구와 특성을 반영한 인터페이스 방법들을 요구하기 시작하였다. 이에 따라 일반적 성향에 맞추어진 Universal UI와 개인의 특성에 맞춰진 Customizing UI의 양립적 이슈는 지속적으로 대치되어 왔다. 그러므로 이를 서로 적절한 수준에서 상호 보완하여 디자인하는 것은 그 형태나 속성을 떠나 최신 UI의 기본적인 필요충분조건이 되었다. Universal UI는 인식과 행동패턴을 달리하는 사람들의 공통분모를 찾아냄으로써 표준화의 Solution을 찾아낼 수 있었지만 Customizing에 대한 해답은 사용자 심리, 문화, 역사까지 고려해야 한다. 우리는 이 두 부분을 모두 만족하는 다방면의 멘탈모델 수립과 UT검증을 통해 모바일 기기에서 최적의 인터페이스 개발을 진행하게 되었다. 이러한 Customizing에 대한 연구는 기기 사용자의 지역과, 문화적 특성에 따라 최적화된 인터페이스를 제공할 수 있기에 기기 제조사는 Future work을 위해서라도 이러한 부분에의 충분한 연구 의의가 있다고 할 수 있다. 우리는 본 논문에서와 같은 Personalization과, 선호 기능을 좀 더 쉽게 적응하고 사용할 수 있도록 하는 Customization 을 통해 사용자의 성향을 적극 반영할 수 있는 모바일 인터페이스 제품 개발로 한 단계 발전시켰다고 본다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.623-630
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• 2016

Heterogeneous IoT devices must satisfy a certain level of security for mutual connections and communications. However, a performance degradation of cryptographic algorithms in resource constrained devices is inevitable and so an optimization or efficient implementation method is necessary. In this paper, we study an efficient implementation method for rotation operations regarding registers for running ARX lightweight block ciphers. In a practical sense, we investigate the performance of modified rotation operations through experiments using real experiment devices. We show the improved performance of modified rotation operations and discover the significant difference in measured performance between simulations and real experiments, particularly for 16-bit MSP microcontrollers.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.3
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• pp.177-185
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• 2017

In this paper, we proposed a concept of interference load to analyze the performance of spectrum sharing technologies in unlicensed frequency bands. The interference load can quantitatively compare the technical properties of various spectrum sharing technologies, such as frequency hopping(FH), duty cycle(DC), listen-before-talk(LBT). Therefore, it can help to evaluate whether a local regulation about spectrum sharing is reasonably established or not. In order to verify the suggested concept, we applied it to 2.4 GHz frequency bands. Also, we demonstrated a real-time test-bed. Two bit error rate(BER) curves for FH with 10 random channels and DC of 10 %, show such good agreement that our proposed concept is expected to be widely used to assess various spectrum sharing technologies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.845-851
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• 2019

We design, implement, and evaluate a user-level ad hoc network routing protocol on the COTS (commercial off-the-shelf) mobile devices. In situations such as disaster recovery, emergency communication between mobile devices is necessary. For wide deployability and usability of such a system, we design and implement the networking protocols on the user level instead of modifying the kernel of mobile devices. In order to support reliable data transfer in high mobility scenarios, we selected to implement AODV (Ad Hoc On-Demand Distance Vector) as the routing protocol and TCP as the transport layer protocol. With our implementation of ad hoc networking stack on COTS smartphones, we conducted experiments in various networking environments. Our experimental results show that ad hoc networking is possible in up to 12 hops in a line topology and 5 concurrent devices in a star topology.

• Annual Conference of KIPS
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• 2015.10a
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• pp.610-612
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• 2015

사물 간 인터넷 환경에서는 IT 융합 기술의 급속한 성장을 통해 지능화된 기기들이 서로 협력함으로써, 인간은 더욱 편리한 생활을 보장받는 반면, 개인의 사생활은 보안위협에 쉽게 노출된다. 다양한 편의 서비스를 제공하기 위해 고객의 개인 정보가 포함된 데이터를 수집하고 처리하는 과정에서 예기치 않은 보안사고가 발생할 수 있다. 검증되지 않은 정보 이용에 의한 경제적 손실 및 안전사고, 무분별한 정보 수집으로 인한 개인 정보 노출 등 서비스를 이용하는 사용자들이 다양한 경로로 위협받을 수 있다. 본 논문에서는 일괄검증이 가능한 비연계성 익명 인증을 제안한다. 비연계성 인증은 동일한 주체가 생성한 메시지인지도 구별불가능하게 만드는 성질로, 강화된 사생활 보호를 제공할 수 있다. 그리고 제안한 비연계성 기법은 일괄검증이 가능한 구조이기 때문에, 다수의 서명 메시지 검증 시, 서명 검증 소요 시간을 크게 단축시킬 수 있다.

• Informatization Policy
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• v.27 no.3
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• pp.39-55
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• 2020

This study was designed to analyze the relationship among the motivations for the use of digital devices, attitudes toward the use of digital devices and performance resulting from the use of digital devices in middle-aged and elderly groups by using a path analysis. For an empirical analysis, the 2018 Survey on the Digital Divide by the National Information Society Agency was referenced, analyzing the data of 1,664 people, selected through listwise deletion from total 2,303 people aged 55 or over. A close examination of how measuring variables reflect potential variables (motivations for, attitudes toward and performance resulting from the use of digital devices) showed a significance of 0.001, which suggests that each individual measuring variable does reflect the potential variables. Evaluation of the pathway factors of the structural model from the motivations for the use of digital devices to the attitudes toward the use of digital devices (β=0.847) and from the attitudes toward the use of digital devices to the performance resulting from the use of digital devices (β= 0.745) revealed significant statistical effects. The results of this study suggest that the motivations for the use of digital devices does not directly enhance the digital device use performance, but that it can improve the attitudes toward the use of digital devices, which can in turn increase the performance resulting from the use of digital devices. The analysis holds significance that it has presented practical and policy implications.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.137-145
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• 2015

Mobile's health care and diagnostic capabilities are accepted as the most innovative sectors, and the combination with wearable device is being predicted as the future's most promising industries. However, the level of consumer acceptance and utilization is still insufficient compared to the development of technology. This study explores the use intention of wearable device based on previous studies about health apps. In particular, health-related use efficacy of the app, app use intention and app satisfaction are analyzed through a structural equation model. The use of health-related apps revealed that there is a statistically significant relationship with the use of the wearable device. The results suggest that the importance of app use efficacy, satisfaction, apps use should be considered for the successful diffusion of wearable health devices.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.1-7
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• 2021

The IoT market continues to expand and grow, but the security threat to IoT devices is also increasing. However, it is difficult to apply the security technology applied to the existing system to IoT devices that have a problem of resource limitation. Therefore, in this paper, we present a service that can improve the security of IoT devices by presenting authentication and lightweight cryptographic algorithms that can reduce the overhead of applying security features, taking into account the nature of resource limitations of IoT devices. We want to apply these service to home network IoT equipment to provide security. The authentication and lightweight cryptographic algorithm application protocols presented in this paper have secured the safety of the service through the use of LEA encryption algorithms and secret key generation by users, IoT devices and server in the IoT environment. Although there is no difference in speed from randomly generating secret keys in experiments, we verify that the problem of resource limitation of IoT devices can be solved by additionally not applying logic for secret key sharing to IoT devices.