• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.625-633
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• 2015

The effect of altitude on thermal conduction, surface temperature, and thermal radiation of partial arc was investigated on the basis of molecular gas dynamics to facilitate a deep understanding of the pollution surface discharge mechanism. The DC flashover model was consequently modified at high altitude. The validity of the modified DC flashover model proposed in this paper was proven through a comparison with the results of high-altitude simulation experiments and earlier models. Moreover, the modified model was found to be better than the earlier modified models in terms of forecasting the flashover voltage. Findings indicated that both the thermal conduction coefficient and the surface thermodynamics temperature of partial arc had a linear decrease tendency with the altitude increasing from 0 m to 3000 m, both of which dropped by approximately 30% and 3.6%, respectively. Meanwhile, the heat conduction and the heat radiation of partial arc both had a similar linear decrease of approximately 15%. The maximum error of DC pollution flashover voltage between the calculation value according to the modified model and the experimental value was within 6.6%, and the pollution flashover voltage exhibited a parabola downtrend with increasing of pollution.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.12
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• pp.80-86
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• 2003

Elliptic curve cryptosystem(ECC) offers the highest security per bit among the known publick key system. The benefit of smaller key size makes ECC particularly attractive for embedded applications since its implementation requires less memory and processing power. In this paper, we propose a new multiplier structure with configurable output sizes and operation cycles. The number of output bits can be freely chosen in the new architecture with the performance-area trade-off depending on the application. Using the architecture, a 193-bit normal basis multiplier and inversion unit are designed in GF(2$^{m}$ ). It is implemented using HDL and 0.35${\mu}{\textrm}{m}$ CMOS technology and the operation is verified by simulation.

• Annual Conference of KIPS
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• 2008.05a
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• pp.706-709
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• 2008

With the increasing popularity of P2P file sharing and advancement of mobile technologies, mobile P2P has revealed its attraction. Anonymity has become an increasing requirement in mobile networks. To reduce receiving garbage files, file validation and filtering are other requirements in the mobile P2P environment. If there are effective file filtering and validation mechanism, nodes' battery duration will be saved. In this paper, we do an analysis of security and anonymity in P2P file sharing and exchange system in mobile ad hoc environment, and propose a new efficient anonymous protocol, which can provide anonymity by broadcasting with a probabilistic algorithm and hiding real hop count information, the file validation by the file's special hash value and file filtering mechanism through the collaboration of middle nodes.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.110-119
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• 2021

The Coronavirus or COVID-19 is contagiousness virus that infected almost every single part of the world. This pandemic forced a major country did lockdown and stay at a home policy to reduce virus spread and the number of victims. Interactions between humans and robots form a popular subject of research worldwide. In medical robotics, the primary challenge is to implement natural interactions between robots and human users. Human communication consists of dynamic processes that involve joint attention and attracting each other. Coordinated care involves sharing among agents of behaviours, events, interests, and contexts in the world from time to time. The robotics arm is an expensive and complicated system because robot simulators are widely used instead of for rehabilitation purposes in medicine. Interaction in natural ways is necessary for disabled persons to work with the robot simulator. This article proposes a low-cost rehabilitation system by building an arm gesture tracking system based on a depth camera that can capture and interpret human gestures and use them as interactive commands for a robot simulator to perform specific tasks on the 3D block. The results show that the proposed system can help patients control the rotation and movement of the 3D arm using their hands. The pilot testing with healthy subjects yielded encouraging results. They could synchronize their actions with a 3D robotic arm to perform several repetitive tasks and exerting 19920 J of energy (kg.m².S^-2). The average of consumed energy mentioned before is in medium scale. Therefore, we relate this energy with rehabilitation performance as an initial stage and can be improved further with extra repetitive exercise to speed up the recovery process.

• Annual Conference of KIPS
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• 2016.04a
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• pp.259-262
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• 2016

최근 중요 인프라 업계에서 주로 다뤄지는 제어시스템을 표적으로 한 사이버 공격으로 Stuxnet에 이어 Havex RAT, BlackEnergy2 라고 하는 멀웨어(Malware)를 이용한 사건이 많이 증가하고 있다. 제어시스템의 새로운 공격 방법에 대한 대책으로 시스템 입구와 내부조직에 대한 대책을 강화하기 위한 필요성이 요구되어 왔지만 그러한 대책은 한정되어 있다. 본 논문에서는 보안대책에 필요한 인증 취득에 있어서 기준이 되는 국제 표준인 ISASecure(R)EDSA 인증제도에 착목했다. 인증평가는 요구요건이 중복되는 불필요한 인증평가 작업을 최소화 하는 것으로 인증 취득 시 발생되는 코스트를 절감할 수 있으며 기존의 정보 보안 관리체계(lSMS)의 인증을 취득하고 있는 기업이나 조직이면 제어시스템의 인증 기준으로 추가된 차분 요건만으로 취득이 가능 할 수 있을 것으로 상정된다. 이러한 제어시스템의 보안을 구현하기 위해 IACS(Industrial Automation and Control System)에서 표준화로 제정한 IEC62443 시리즈를 참조하여 세계각국에서 사용되는 제어시스템을 대상으로 인증(EDSA) 요구사항의 차분을 도출하는 수법을 제안하고자 한다.

• Journal of Aerospace System Engineering
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• v.13 no.2
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• pp.60-65
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• 2019

TerraSAR-X, launched in June 2007, and TanDEM-X, June 2010, are remote-sensing satellites with 1M resolution that are capable of observing the ground even during the nighttime and poor weather conditions. The two satellites had been developed under a public-private partnership between the German Aerospace Centre and Airbus in the interest of the commercial marketing for German satellite data. However, the data of high-grade earth remote-sensing system, such as those of the satellites, has been produced by a military satellite and thus used under limited circumstances in Germany. Therefore, a legislation to commercialize the German satellite data and to protect its national security is needed. For this, SatDSiG was enacted in December 2007. Thus this article will contain the main contents of SatDSiG and its implication for Korea, which stared to export data of Kompsat 3, 3A and 5 in 2018.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.525-532
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• 2003

This paper describes intrusion detection rule management using mobile agents. Intrusion detection can be divided into anomaly detection and misuse detection. Misuse detection is best suited for reliably detecting known use patterns. Misuse detection systems can detect many or all known attack patterns, but they are of little use for as yet unknown attack methods. Therefore, the introduction of mobile agents to provide computational security by constantly moving around the Internet and propagating rules is presented as a solution to misuse detection. This work presents a new approach for detecting intrusions, in which mobile agent mechanisms are used for security rules propagation. To evaluate the proposed approach, we compared the workload data between a rules propagation method using a mobile agent and a conventional method. Also, we simulated a rules management using NS-2 (Network Simulator) with respect to time.

• Annual Conference of KIPS
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• 2018.10a
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• pp.200-203
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• 2018

최근 기업, 기관, 개인의 자산들에 대한 사이버 위협이 빈번하게 발생되고 있으며, 시장에는 다양한 업체, 제품의 단말/EDR/네트워크 제품들이 경쟁하고 있따. 이로 인해 사이버 위협에 대한 정보 및 제어 정보, 정책 정보들을 사전에 공유하고 해당 정보의 자동화된 해석을 통한 신속한 대응 처리의 중요성이 높아지고 있다. 본 논문에서는 업체들의 장비/제품에 적용 가능한 제어 정보를 정의하고 이를 공유하기 위한 공유 시스템을 제안한다. 이를 위해 STIX 2.0 표준을 도입하여 제어 정보를 설계하고, 확장 표준을 통해 요구되는 속성들을 추가 정의하여 자동화된 해석 및 대응 처리가 가능하도록 설계한다.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.253-257
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• 2011

This study was carried out to solve problems such as radio frequency band depletion, confusion risk, and security loss in existing visible wireless communication systems, and to determine the applicability of next-generation networks. A light-emitting diode (LED) light communication system was implemented with a controlling switching light module using the ATmega16 micro-controller. To solve the existing modulation effect and disturbance in visible light communication, an integrated interface was evaluated with a driving light module and analyzes its reception property. A transmitter/receiver using the ATmel's micro-controller, high-intensity white LED-6 modules, and infrared sensor KSM60WLM and visible sensor TSL250RD were designed. An experiment from the initial value of distance to 2.5 m showed 0.46 V of the voltage loss, and if in long distance, external light interference occurred and light intensity was lost by external impact and thus data had to be modified or reset repeatedly. Additionally, when we used 6 modules through the remote controller's lighting dimming, data could be transmitted up to 1.76 m without any errors during the day and up to 2.29 m at night with around 2~3% communication error. If a special optical filter can reduce as much external light as possible in the integrated interface, the LED for lighting communication systems may be applied in next generation networks.

• ETRI Journal
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• v.39 no.3
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• pp.406-416
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• 2017

Malware propagated via the World Wide Web is one of the most dangerous tools in the realm of cyber-attacks. Its methodologies are effective, relatively easy to use, and are developing constantly in an unexpected manner. As a result, rapidly detecting malware propagation websites from a myriad of webpages is a difficult task. In this paper, we present LoGos, an automated high-interaction dynamic analyzer optimized for a browser-based Windows virtual machine environment. LoGos utilizes Internet Explorer injection and API hooks, and scrutinizes malicious behaviors such as new network connections, unused open ports, registry modifications, and file creation. Based on the obtained results, LoGos can determine the maliciousness level. This model forms a very lightweight system. Thus, it is approximately 10 to 18 times faster than systems proposed in previous work. In addition, it provides high detection rates that are equal to those of state-of-the-art tools. LoGos is a closed tool that can detect an extensive array of malicious webpages. We prove the efficiency and effectiveness of the tool by analyzing almost 0.36 M domains and 3.2 M webpages on a daily basis.