• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1729-1731
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• 2015

스마트 디바이스의 고성능화 초소형화로 사용자의 편리 증대를 위한 다양한 응용 연구가 진행되고 있다. 이러한 응용 연구의 주된 목적은 편리함 및 다양한 서비스 측면을 고려하고 보안 연구는 도외시되고 있어 이와 관련된 개인정보 유출 문제가 발생되고 있다. 이러한 이유로 스마트 디바이스의 다양한 장금 기법이 개발되었지만 주로 사용되는 잠금 기법의 대부분은 사용자가 Key로 사용되는 패스워드를 직접 입력하는 과정을 거쳐야 한다. 이 과정에서 Key가 타인에게 노출될 수 있으며 이는 가장 많이 사용되는 해킹 수법 가운데 하나이다. 본 논문은 스마트 디바이스의 가속도 센서를 활용한 잠금 기법으로 잠금을 해제하는 일련의 추가적인 과정이 없도록 사용자가 디바이스를 손에 쥐고 들어올리는 과정을 Key로 사용하는 TTU(Take To Unlock)를 제시한다. 타인이 보기에 디바이스의 잠금 여부를 추측하지 못하도록 자연스러운 잠금을 제공하는 것이 TTU의 목적이며 동시에 사용자가 Key를 입력해야 하는 추가적인 행위를 최소화 한다.

• Journal of Welding and Joining
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• v.30 no.3
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• pp.32-37
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• 2012

Lead frame which has a high thermal conductivity and high mechanical strength is one of core technology for ultra-thin electronics such as LED lead frames, memory devices of semiconductors, smart phone, PDA, tablet PC, notebook PC etc. In this paper, we fabricated a Cu/STS/Cu 3-layered clad metal for lead frame packaging materials and characterized the mechanical properties and thermal conductive properties of the clad metal lead frame material. The clad metal lead frame material has a comparable thermal conductivity to typical copper alloy lead frame materials and has a reinforced mechanical tensile strength by 1.6 times to typical pure copper lead frame materials. The thermal conductivity and mechanical tensile strength of the Cu/STS/Cu clad metal are 284.35 W/m K and $52.78kg/mm^2$, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.728-736
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• 2007

The more improved the Internet and the information technology, the stronger cryptographic system is required which can satisfy the information security on the platform of personal hand-held devices or smart card system. This paper introduces a case study of designing an elliptic curve cryptographic processor of a high performance that can be suitably used in a wireless communicating device or in an embedded system. To design an efficient cryptographic system, we first analyzed the operation hierarchy of the elliptic curve cryptographic system and then implemented the system by adopting a serial cell multiplier and modified Euclid divider. Simulation result shows that the system was correctly designed and it can compute thousands of operations per a secdond.

• Journal of IKEEE
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• v.23 no.2
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• pp.747-750
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• 2019

Wearable devices have become practically indispensable to daily life and helped people track and manage fitness, health, and medical functions etc. As these wearable devices become smaller and more comfortable for the user, the demand for longer run time and charging ways presents new challenges for the power management engineer. Wireless power transfer (WPT) is the technology that forces the power to transmit electromagnetic field to an electrical load through an air gap without interconnecting wires. This technology is widely used for the applications from low power smart phone to high power electric railroad and main electrical grid. There are two kinds of WPT methods: Inductive coupling and magnetic resonant coupling. The model using magnetic resonant coupling method is designed for a resonant frequency of 13.45 MHz. In this study, the hardware implementations of these two coupling methods are carried out, and the efficiencies are compared.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.193-200
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• 2019

Hearing impaired people are living in a voice culture area, but due to the difficulty of communicating with normal people using sign language, many people experience discomfort in daily life and social life and various disadvantages unlike their desires. Therefore, in this paper, we study a sign language translation system for communication between a normal person and a hearing impaired person using sign language and implement a prototype system for this. Previous studies on sign language translation systems for communication between normal people and hearing impaired people using sign language are classified into two types using video image system and shape input device. However, existing sign language translation systems have some problems that they do not recognize various sign language expressions of sign language users and require special devices. In this paper, we use machine learning method of artificial neural network to recognize various sign language expressions of sign language users. By using generalized smart phone and various video equipment for sign language image recognition, we intend to improve the usability of sign language translation system.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1275-1280
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• 2018

We made a smartphone interlocking location tracking streetlight and remote display device to compensate the defect of real time identifiable CCTV streetlights and child safety notification applications. It controls brightness of LED by detecting the surrounding brightness and objects with ultrasonic sensor and illuminance senor. The CCTV receives the location of smartphone by Bluetooth and takes the target of the location. It realizes a wireless transmission system that the video is upload to the tablet PC via WiFi.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.593-595
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• 2016

In recent, the cafe culture has came very close friendly people. But many customers have been left the seat because the cafe has been heavily biased. To solve the problem, we propose the Cafe Seat Confirmation System based on IoT. Proposed system consists of Arduino, Raspberry Pi, and application. Using a smart device, it is possible to provide efficient services such as real-time seat reservations and cafes management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.387-389
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• 2014

It is preferred to the popularization of smart device business processes through mobile. The ratio of Internet access via mobile devices is reached 30% of PC in September 2012. It is reproduced in a mobile environment that security threats arising from the Internet. that is the characteristics of cyber security threats appearing on the mobile era. Web Application Service security research firm OWASP (The Open Web Application Security Project) issued Session Management threat. That threat will be reproduced in the mobile environment. But Mobile is significantly different from Desktop Computer about Session Management environment. This proceeding proposes a improved Session Management method in Mobile environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.159-160
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• 2019

It would be very important to localize people at risk as soon as possible in order to minimize the damage. Generally the infrastructure should be deployed additionally for indoor positioning system. In this paper, we proposed an indoor localization system for people at risk using the existing fire alarm networks. The system detects the signal of smart devices of people in danger immediately and let the main alarm controller ring all alarms in vessel and display the position. Thus, the proposed system can make the burden much less to deploy additional network and infrastructure.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.79-86
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• 2019

This paper is an overview of key elements of Korea National Open University's smart mobile learning system, and an attempt to evaluate its main services relative to the FRAME model and the Mobile Learning Development Model for distance learning in higher education. KNOU improved its system architecture to one based on xMOOC e-learning content delivery while also upgrading its PC-based online/mobile learning services to facilitate an easier and more convenient access to lectures and for better interactivity. From the users' viewpoint, the upgraded 'U-KNOU Campus' allows for a more integrated search capability coupled with better course recommendations and a customized notification service. Using the new system, the students can access not only the school- and peer-issued messages via online bulletin boards but also share information and pose questions to others including to the school faculty/officials and system administrators. Additionally, a new mobile payment method has been incorporated into the system so that the students can select and pay for additional courses from anywhere. In spite of these advances, the issue of device usability and content development remain; specifically U-KNOU Campus needs to improve its instructor-learner and learner-to-learner interactivity and mobile evaluation interface.