• Journal of IKEEE
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• v.24 no.1
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• pp.46-51
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• 2020

With Wi-Fi and Bluetooth connectivity becoming more common in today's handheld mobile devices, single-chip multi-radio combo-modules, which integrate two or more heterogeneous wireless radios on a single chip, are becoming more and more popular. The key requirement for combo solutions is that the quality of the user experience (QoE) must not be compromised by degrading connectivity performance. Therefore, characterizing and understanding the behaviour of combo-module is of vital importance to ensure this requirement in various environments. In this paper, we investigate the impact of the use of combo-modules on the performance of mobile video streaming over a Wi-Fi network. Our study reveals that the use of combo-modules incurs considerable side effects on QoE for mobile video streaming applications when the Wi-Fi and Bluetooth operate at the same time in the 2.4GHz ISM band. We reveal that rate-based adaptive algorithms, including the most popular adaptive bitrate streaming MPEG-DASH, is more severely affected by this phenomenon than buffer-based adaptive algorithms.

• Journal of Engineering Education Research
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• v.10 no.4
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• pp.78-92
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• 2007

This study presents how the engineering ethics instructional modules have been developed based on Korean culture and how they are implemented into the existing engineering curricula at Sungkyunkwan University. The engineering ethics instructional modules were designed to be taught by engineering faculty members who did not have any teaching experience in ethics. As a result, it was determined that the engineering ethics instructional modules should include a detailed instructor lesson plan and all supporting resources such as slides (Power Point base), and handouts, or assessment units (pre- and post-test). Two 75 minute modules developed in this study consist of the diverse instructional activities for various student group sizes. In order to improve students' interests and classroom attention, various visual and audio resources such as famous movies, cartoons, and poems were included in the instructional resources. In addition, a number of case studies which might happen in the students' daily lives were chosen. The resulting ethical module No. 1 has been instructed in the existing engineering classes during the 1st semester in 2007. Overall, the students reported positive impressions of the modules and the faculty members also reported favorable perceptions of the modules. Also, team based activities encouraged students to participate in constructing the event trees, which are a basic analysis tool for ethics case studies. The results of this study will provide a guideline of implementing engineering ethics into the engineering curricula to other engineering programs and schools.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.39-40
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• 2015

본 논문에서는 대용량의 영상을 빠르고 정확하게 편집해야 하는 방송 환경에서 오픈 소스를 활용한 방송용 영상 편집 시스템과 편집 결과를 신속히 통보하는 다기능 알람 시스템에 대하여 다루었다. 디지털 방송에서 사용하는 영상은 매우 고품질이면서 동시에 매우 큰 데이터 용량을 가지고 있으며, 또 방송이라는 매체의 성격상 방송 시간에 맞춰 영상 편집을 완료해야 하는 시간적 부담이 있다. 본 논문에서 제안하는 방송 편집 시스템은 갈수록 그 기능이 다양하고 좋은 성능을 보여주는 오픈 소스 영상 처리 소프트웨어를 활용하는 동시에, 분산 처리 시스템을 도입하여 영상의 빠른 편집 기능을 저렴한 도입 비용으로 가능하도록 하였다. 오픈 소스 영상 처리 소프트웨어는 백엔드 모듈로 동작하며, 영상의 다양한 편집 기능들, 예를 들어 영상의 구간 자르기, 붙이기, 자막넣기, 로고 넣기, 비디오/오디오 포맷 변환 등을 수행한다. 사용자 편의성을 위한 프론트엔드 시스템은 자바 기반의 프레임워크를 사용하였으며, 비디오 편집 기능 결과 및 과정에 대한 다기능 알람 기능을 첨가하여 방송 종사자들의 업무 편리를 도모하였다. 본 시스템은 기존의 고가 방송 편집 장비와 비교하여 매우 저렴하면서도 안정된 성능을 보장하여 디지털 방송 시대에 활용 가능성이 매우 높다고 할 수 있다.

• The KIPS Transactions:PartA
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• v.12A no.4 s.94
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• pp.313-320
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• 2005

The 2-D discrete cosine transform (DCT) is an integral part of video and image processing; it is used in both the PEG and MPEG enciding standards. As streaming video is brought to mobile devices, it becomes important that it is possible to calculate the DCT in an energy-efficient manner. In this paper, we present a new algorithm the DCT with a linear array PEs. This design is optimized for energy efficiency. We analyze the energy, area, and latency tradeoffs available with this design and then compare its energy dissipation, area, and latency to those of Xilinx's optimized IP core.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4780-4785
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• 2012

As many mobile devices such as smart phones and tablets are widely spread, optimized mobile video encoder used during video recording application is needed. In this paper, we implemented H.264/AVC base profile video encoder on a mobile device and empirically optimized control parameters of the encoder. As the experiment, we more than 100 test cases were designed with varying Lagrangian optimization, Hadamard Transform, search range, I-frame period, and reference frames. During the experiment, we measured picture quality, bit-rate, encoding time, motion estimation time, and power consumption. From the result, we can determine optimal values for the H.264 control parameters.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.43-50
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• 2016

In this paper, we present a distortion correction for wearable Augmented Reality (AR) on mobile phones. Head Mounted Display (HMD) using mobile phones, such as Samsung Gear VR or Google's cardboard, introduces lens distortion of the rendered image to user. Especially, in case of AR the distortion is more complicated due to the duplicated optical systems from mobile phone's camera and HMD's lens. Furthermore, such distortions generate mismatches of the visual cognition or perception of the user. In a natural way, we can assume that transparent wearable displays are the ultimate visual system which generates the least misperception. Therefore, the image from the mobile phone must be corrected to cancel this distortion to make transparent-like AR display with mobile phone based HMD. We developed a transparent-like display in the mobile wearable AR environment focusing on two issues: pincushion distortion and field-of view. We implemented our technique and evaluated their performance.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.4
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• pp.23-31
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• 2018

This paper presented the implementation and design of the 2T-2R wireless HD video streaming systems over 1.7 GHz frequency band using 3GPP LTE-TDD standard on NI USRP RIO SDR platform. The baseband of the system used USRP RIO that are stored in Xilinx Kintex-7 chip to implement LTE-TDD transceiver modem, the signal that are transmitted from USRP RIO up or down converts to 1.7 GHz by using self-designed 1.7 GHz RF transceiver modules and it is finally communicated HD video data through self-designed 2x9 sub array antennas. It is that communication method between USRP RIO and Host PC use PCI express x4 to minimize delay of data to transmit and receive. The implemented system show high error vector magnitude performance above 32 dBc and to transmit and receive HD video in experiment environment anywhere. The proposed hybrid beam forming system could be used not only in the future 5G mobile communication systems under 6 GHz frequency band but also in the systems over 6 GHz frequency band like ones in mmWave frequency bands.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.147-151
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• 2014

With the advent of tiny and inexpensive computer systems like Raspberry Pi, it has become possible to construct an experimental environment of MANETs (Mobile Ad hoc Networks) at a relatively low cost. In this paper, we implement a node of MANETs with a Raspberry Pi equipped with two 802.11 wireless LAN cards and dynamic routing software running on it. In an outdoor MANETs environment with moving mobile nodes automatically rebuilding broken routes, we conducted a real-time video streaming experiment over the MANET. The video stream is transmitted from a node with a video camera installed on it to another node through the route established dynamically. Each node is equipped with a display device, with which the current status of the node can be checked out. We also implemented software that automatically collects data stored in each node and analyzes the performance of the MANETs. Through this experiment, we could evaluate the performance of realistic video streaming service in a MANETs environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4A
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• pp.390-398
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• 2004

This paper describes a study on the automatic generation system of the interface for communication among AMBA bus and IPs with different protocols. Employing an extended STG, the proposed system generates the interface modules required for the communication among IPs with different protocols. For an example system, the interface module for communication between AMBA AHB bus and a video decoder has been generated and verified in its functionality. The area and latency have been compared with the manually designed interface. For burst-mode communication, the generated interface module shows the comparable performance with the manually designed module. For single-mode communication, the generated interface module shows a slightly worse performance than the manually designed module. However, the increased area is negligible considering the size of the IP.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1109-1116
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• 2023

Object tracking is used to track a goal in a video sequence by using coordinate information provided as annotation in the first frame of the video. In this paper, we propose a tracking algorithm that combines deep features and region inference modules to improve object tracking accuracy. In order to obtain sufficient object information, a convolution neural network was designed with a Siamese network structure. For object region inference, the region proposal network and overlapping confidence module were applied and used for tracking. The performance of the proposed tracking algorithm was evaluated using the Object Tracking Benchmark dataset, and it achieved 69.1% in the Success index and 89.3% in the Precision Metrics.