• ETRI Journal
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• v.39 no.2
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• pp.202-212
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• 2017

With the advent of the Internet-of-Things paradigm, the amount of data production has grown exponentially and the user demand for responsive consumption of data has increased significantly. Herein, we present DART, a fast and lightweight stream processing framework for the IoT environment. Because the DART framework targets a geospatially distributed environment of heterogeneous devices, the framework provides (1) an end-user tool for device registration and application authoring, (2) automatic worker node monitoring and task allocations, and (3) runtime management of user applications with fault tolerance. To maximize performance, the DART framework adopts an actor model in which applications are segmented into microtasks and assigned to an actor following a single responsibility. To prove the feasibility of the proposed framework, we implemented the DART system. We also conducted experiments to show that the system can significantly reduce computing burdens and alleviate network load by utilizing the idle resources of intermediate edge devices.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.4
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• pp.294-301
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• 2016

In this paper, we present methods to efficiently parallelize iterative 3D image reconstruction by exploiting trigeneous devices (three different types of device) at the same time: a CPU, an integrated GPU, and a discrete GPU. We first present a technique that exploits single instruction multiple data (SIMD) architectures in GPUs. Then, we propose a performance estimation model, based on which we can easily find the optimal data partitioning on trigeneous devices. We found that the performance significantly varies by up to 6.23 times, depending on how SIMD units in GPUs are accessed. Then, by using trigeneous devices and the proposed estimation models, we achieve optimal partitioning and throughput, which corresponds to a 9.4% further improvement, compared to discrete GPU-only execution.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.227-240
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• 2020

This paper proposes a novel CTC technology, CB-sense. The CB-sense guarantees a dedicated period for the CTC that results in low duty cycle of the receiver device. In addition, it send a lot of information explosively during the dedicated CTC period. Thus, it can achieve high throughput. The CB-sense uses Clear to Send (CTS) packets to transmit information bits to the heterogeneous wireless technologies. The CTS packets block the neighboring node transmissions, so it reduces co-channel interference. In experiment results, CB-sense represents 20 times more throughput than FreeBee and below 5% symbol error rate in the interference environment.

• Journal of the military operations research society of Korea
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• v.29 no.1
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• pp.57-75
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• 2003

Policy-based networking offers a network manager the ability to manage the network in a holistic and dynamic fashion rather than force a network manager to manage the network by dealing with each device individually. Policy-based networking is focusing on users and applications instead of emphasizing devices and interfaces. An important part of the policy-based networking is to simplify the task of administration and management for different disciplines. The Defense Information System(DIS) of today are complex and heterogeneous systems. Operational needs are not a trivial task and Quality of Service(QoS) is not generally guaranteed. So, important data may be missed or congested by trivial data. Policy-based networking provide a way to support QoS and simplify the management of multiple devices deploying complex technologies. This paper suggest implementation of policy-based networking in DIS to improvement of performance, and implementation is progressed step by step. Especially this paper is focusing on the providing QoS with policy-based networking using Lightweight Directory Access Protocol(LDAP) Server.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1279-1282
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• 2017

현재 사물인터넷(Internet of Things; IoT) 기술을 이용한 스마트홈 환경을 구축하기 위해서는 같은 식별체계를 사용하는 플랫폼 디바이스를 사용해야 한다. 그러나 주요 IoT 플랫폼들은 각각 다른 식별체계를 사용하고 있기 때문에 이종 플랫폼 간 디바이스 식별이 어려운 상황이다. 이종 플랫폼 간 디바이스 식별체계 상호연동에 대한 연구는 진행 중이며 아직까지 해결책은 제시되지 않았다. 따라서 본 논문에서는 주요 IoT 플랫폼인 oneM2M, GS1 Oliot, IBM Watson IoT, OCF IoTivity의 디바이스 식별체계를 분석하고 비교하여 서로 다른 플랫폼 간 디바이스 식별체계에 대한 번역기 또는 해석기의 필요성과 개념모델을 제시한다.

• ETRI Journal
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• v.36 no.4
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• pp.617-624
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• 2014

Through-silicon via (TSV) technology provides much of the benefits seen in advanced packaging, such as three-dimensional integrated circuits and 3D packaging, with shorter interconnection paths for homo- and heterogeneous device integration. In TSV, a destructive cross-sectional analysis of an image from a scanning electron microscope is the most frequently used method for quality control purposes. We propose a quantitative evaluation method for TSV etch profiles whereby we consider sidewall angle, curvature profile, undercut, and scallop. A weighted sum of the four evaluated parameters, nominally total score (TS), is suggested for the numerical evaluation of an individual TSV profile. Uniformity, defined by the ratio of the standard deviation and average of the parameters that comprise TS, is suggested for the evaluation of wafer-to-wafer variation in volume manufacturing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.277-278
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• 2017

Recently, many industrial instruments face the problem of protocol compatibility with the external monitoring and control system. This paper implemented a protocol conversion algorithm for industrial monitoring about communication Data. This algorithm is supported programmable method by user. we experimented the protocol conversion by communication gateway module using implemented algorithm, and obtained good results.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.50-57
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• 2018

As devices have evolved, traditional flip chip bonding and recently commercialized thermocompression bonding techniques have been limited. Laser-assisted bonding is attracting attention as a technology that satisfies both the requirements of mass production and the yield enhancement of advanced packaging interconnections, which are weak points of these bonding technologies. The laser-assisted bonding technique can be applied not only to a two-dimensional bonding but also to a three-dimensional stacked structure, and can be applied to various types of device bonding such as electronic devices; display devices, e.g., LEDs; and sensors.

• Journal of the Semiconductor & Display Technology
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• v.20 no.1
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• pp.113-117
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• 2021

A composite active layer was designed based on graphene quantum dots, which is a low-dimensional structure, and a heterogeneous active layer of graphene quantum dots was applied to the interfacial defect structure to overcome the limitations. Increasing to 1.5~3.5 wt % PVP GQD, Vf changed from 2.16 ~ 2.72 V. When negative deflection is applied to the lower electrode, electrons travel through the HfOx/ITO interface. The Al + ions are reduced and the device dominates at low resistance. In addition, as the PVP GQD concentration increased, the depth of the interfacial defect decreased, and the repetition of appropriate electrical properties was confirmed through Al and HfOx/ITO. The low interfacial defects help electrophoresis of Al+ ions to the PVP GQD layer and the HfOx thin film. A local electric field increase occurred, resulting in the breakage of the conductive filament in the defect.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.97-99
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• 2013

Various display devices become widespread now. Endeavoring to provide high-quality user experience, sharing contents becomes a hot issue in recent years. In this paper, a Contents Sharing System based on Users Context is proposed, which can provide pervasive contents sharing services on multiple devices with disregard for the device differences. This system supporting automatical contents sharing according to users' context, and intelligent content-fault recovery to provide an intelligent platform for users sharing service seamlessly without additional manual operations. Also we points out the problems and considerations about this proposed system which will be improved in the later research.