• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.3
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• pp.58-63
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• 2000

For the microwave high density devices and modules of the 3D configuration, we proposed radial stub for the ground connection. The proposed structure is analyzed by the full-wave analysis of finite element method (FEM) and characterized experimentally. The results show that the return loss is more than 15 dB and the insertion loss is less than 0.5 dB in the frequency range from 2.5 GHz to 6.3 GHz. The proposed grounding scheme will be useful for the ground connection lot the microwave high density devices and module of 3D configuration.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1027-1034
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• 2011

Electronic devices in railway vehicle perform various functions such as not only braking and propulsion but also monitoring of vehicle condition, on-line diagnosis, and passenger information service, etc. These devices, distributed in vehicle, should be efficiently connected so as to properly perform the functions. IEC (International Electro-Technical Commission) standardized train communication network (TCN) as IEC 61375-1, -2. TCN can reduce the interconnecting work load by reducing the number of wire-line, compared with existing hard-wire connection, and it brings the efficient control by enabling various devices to share the information. But existing TCN can not satisfy the increasing service demands like passenger internet access and CCTV surveillance, etc. In this paper, we investigate ECN (Ethernet Consist Network) and ETN (Ethernet Train Backbone) which are proposed to satisfy these demands and in the process of standardization by IEC TC9 WG43.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.1033-1040
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• 2014

Recently, the concept of mobile content service has changed from providing unilaterally contents for single-device to providing same contents for multi-device. This service should be able to provide diverse contents for multi-devices without platform and specification of multi-device. In this study, we propose a bridge technique of heterogeneous smart platform supporting social immersive game. It is possible to access social immersive game by using a multi-platform bridge. To achieve this, we explain techniques of device connection and data transmission between heterogeneous devices using server-client structure and UPnP. It provides an immersive game environment for multi-user, which is able to play in a public place using big screen.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.198-201
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• 2001

Recently the wireless-internet has been spreading extensively. People are spending a large part of their time gaining access to information using a mobile device. With the rapid growth of on-line Electronic Commerce, the use of mobile devices creates a new paradigm that provides users with location-independent real time service. Although this new paradigm does have some advantages, limited process speed, low bandwidth, the low battery capacity of mobile devices, and a high rate of wireless network errors causes many overhead expenses during service time with the server. In this paper, we suggest an autonomous service delivery system, which provides mobile agent capability to users that cannot maintain a connection. We have developed the system based on java mobile agent technology. Using this system, we can provide more effective service to users when the user is sending requirements for service through a mobile device that has limited resources. Furthermore we can manage the contact server dynamically when new services are added.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.116-118
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• 2000

The modern power system including lots of measuring devices and controller is large and complex total information system. A Lot of data and system information are transmitted to operators, and analysing these information and system management is very important. Recently, GUI(Graphic Users Interface) is emphasized as a method that operators carry out their duties, effectively. In this paper. a simulator that can show state estimation and detection of bad measuring devices is introduced for domestic 154kV/22.9kV distribution substations. C language and Visual Basic is used for this simulator. and TCP/IP is adopted to consider connection with a Power system.

• Journal of Korea Multimedia Society
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• v.17 no.4
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• pp.405-412
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• 2014

Due to the popularity of mobile phones, Peer-to-Peer (P2P) content sharing in mobile phones is highly desirable, especially in a mobile data connection. In addition, there has been an increasing demand for content sharing applications for P2P communication in Android-based smartphones as ubiquitous mobile devices. However, due to wireless network limits, unstable characteristic and restricted storage space, mobile users confront challenges in establishing connections and sharing video frames with other users. To solve this issue, we propose an architectural design and implementation of key frame sharing application that uses Chord, a distributed lookup protocol to establish a content sharing platform for mobile devices, combined with the Chord SDK based on Android. Our proposed system enables users easily to share key information on video data in real-time over a wireless network without manual processing of devices which join or leave the group and cost associated with the 3G/4G network.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.290-293
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• 2002

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor connection scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and experimental implementations.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.203-206
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• 2012

The System of communication with wireless devices is experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. In order to realize service mobility, there is a need of protocol that can support mobility while nodes are communicating without any disruption of their connection status. This paper proposes a handover authentication protocol for mobility support. Careful considerations must be taken in priority to security issues since many unreliable public and private resources; both networks and devices are involved. The protocol is based on public key cryptography with Diffie-Hellman algorithm which provides security against both leakage-resilience of private keys on untrustworthy devices and forward secrecy.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.1-5
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• 2019

As the number of IOT devices is growing rapidly, various 'see-thru connection' techniques have been reported for efficient communication with them. In this paper, we propose a deep learning based IOT device recognition system for interaction with these devices. The overall system consists of a TensorFlow based deep learning server and two Android apps for data collection and recognition purposes. As the basic neural network model, we adopted Google's inception-v3, and modified the output stage to classify 20 types of IOT devices. After creating a data set consisting of 1000 images of 20 categories, we trained our deep learning network using a transfer learning technology. As a result of the experiment, we achieve 94.5% top-1 accuracy and 98.1% top-2 accuracy.

• Convergence Security Journal
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• v.21 no.1
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• pp.63-72
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• 2021

The hospital biomedical engineering team is responsible for establishing and regulating the Medical Device Management Program (MEMP) to ensure that medical devices are safe and reliable. As technology advances, medical devices such as artificial intelligence and precision medicine are developing into a form that allows connection between objects anytime, anywhere, and as various technologies converge, internal and external security threats continue to increase. In this paper, we present a study of the Medical Device Management Program (Secure-MEMP) method, considering that the security threat of medical devices continues to increase due to advances in technology.