• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1161-1162
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• 2023

모바일 로봇의 자율주행을 위하여 인터넷이 제약된 환경에서도 가능한 Edge computing 에서의 Object Detection 이 필수적이다. 본 논문에서는 이를 위해 Orin 보드에서 YOLOv7 과 Complex_YOLOv4 를 구현하였다. 직접 취득한 데이터를 통해 YOLOv7 을 구현한 결과 0.56 의 mAP 로 프레임당 133ms 가 소요되었다. Kitti Dataset 을 통해 Complex_YOLOv4 를 구현한 결과 0.88 의 mAP 로 프레임당 236ms 가 소요되었다. Comple_YOLOv4 가 YOLOv7 보다 더 많은 데이터를 예측하기에 시간은 더 소요되지만 높은 정확성을 가지는 것을 확인할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.383-393
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• 2010

DVC (Distributed Video Coding) allows us to explore the video statistics at the decoder side, resulting in a less complex encoder and more complex decoder. In this approach, it is important to generate a good prediction to the current Wyner-Ziv frame, called side information, which plays a crucial role in the overall performance of a DVC system. Conventional MCFI (motion compensated frame interpolation) techniques, which explore temporal correlations between neighbor frames of the current frame, preform the block-based or object-based motion estimation, but, they do not include the basis frame for the Wyner-Ziv frame. This paper proposes an efficient way to get better side information, by finding the average frame between neighbor frames and by comparing adaptively the candidate blocks. Through computer simulations, it is shown that the proposed method can improve the performance up to 0.4dB and provide better subjective and objective visual qualities in Wyner-Ziv CODEC.

• Journal of Adhesion and Interface
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• v.23 no.4
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• pp.108-115
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• 2022

In this study, we synthesized poly(itaconic acid-co-acrylamide) (IAcAAM) used as a novel polymer adhesion promoter to improve the adhesion strength of surface-treated Cu lead frames and epoxy composites. IAcAAM comprising itaconic acid, acrylamide was prepared through radical aqueous polymerization. The chemical structure and properties of IAcAAM was analyzed by FT-IR, ¹H-NMR, GPC, and DSC. The surface of the copper lead frame was treated with high temperature, alkali, and UV ozone to reduce the water contact angle and increase the surface energy. The adhesive strength of Cu lead frame and epoxy composite increased with the decrease of contact angle. The adhesive strength of Cu lead frame/epoxy composite increased with the addition of IAcAAM in epoxy composite. As silica content increased, the adhesive strength of Cu lead frame and epoxy composite tended to slightly decrease.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.7-16
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• 2010

In this paper, we propose an ambient light control method based on the difference of image frames in video. The proposed method is composed of three steps. 1) The first step is to extract a dominant color of a current frame. 2) The second step is to compute the amount of change and the representative color in the changed region using the difference image. 3) The third step is to make a new representative color. The difference image is created from two images transformed into the YUV color space. The summed color difference of each pixel is used for the amount of change. The new representative color is created by synthesizing the current color and the changed color in proportion to the amount of change. We compare the variations of the light effect according to time with and without the proposed method for the same video. The result shows that the new method generates more dynamic light effects.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.271-273
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• 1999

본 논문에서는 CELP 부호화기의 계산량을 줄이면서도 고음질의 음성을 합성할 수 있는 코드북 구조를 제안한다. 제안한 코드북 구조는 불규칙 코드북과 희박 중첩형 코드북 두 개의 코드북의 합으로 여기 신호를 표현한다. codebook I에서 잔류신호와 오차가 적은 여기신호열을 구한 후, 이 여기신호열에 codebook II의 여기신호열을 합하여 최적의 여기신호열을 구한다. 또한 이로 인한 전송비트수의 증가를 막기위해 홀수 프레임에서는 두 개 코드북의 index를, 짝수 프레임에서는 codebook I의 여기신호열은 그대로 사용하고 codebook II에서만 검색하여 전송하는 방법을 사용하였다. 이러한 2중 코드북 구조는 두 개의 여신호열의 합으로 표현되고 각각의 서로 다른 코드북 이득을 사용하기 때문에 정확한 이득을 표현할 수 있어 기존의 개선 알고리듬보다 더 나은 음질을 제공할 수 있다. 검색시간이 빠르고, 본 코드북 구조를 갖는 4.8kbps CELP형 부호화기를 설계하여 컴퓨터 모의 실험한 결과, 같은 전송률을 갖는 DoD CELP 부호화기보다 segSNR가 0.53dB 더 높게 나타났다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1019-1024
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• 2006

A system design and realization for real time DVR system with robust video watermarking algorithm for contents security is presented in this paper. The robust video watermarking is used the intraframe space region and interframe insertion simultaneously, and to be processed at real time on image data and algorithm is used the 64bits special purpose quad DSP processor with assembly and soft pipeline codes. The experimental result shows that the processing time takes about 2.5ms in the D1 image per frame for 60% moving image.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.125-137
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• 2004

In case of using image sequence taken from a moving camera along a road in an urban area, general video mosaicing technique based on a single baseline cannot create 2-D image mosaics. To solve the drawback, this paper proposed a new image mosaicing technique through 3-D multi-baselines that can create image mosaics in 3-D space. The core of the proposed method is that each image frame has a dependent baseline, an equation of first order, calculated by using ground control point (GCP) of optical flows. The proposed algorithm consists of 4 steps: calculation of optical flows using hierarchical strategy, calculation of camera exterior orientation, determination of multi-baselines, and seamless image mosaics. This paper realized and showed the proposed algorithm that can create efficient image mosaics in 3-D space from real image sequence.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.305-313
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• 2020

Telemetry system is a system that transmits status information data acquired from the aircraft to the ground station. PCM encoder needs memory to store channel information in order to generate a frame format using the acquired data. Generally, telemetry systems in large aircraft require much larger memory for the increased acquisition channel information due to the increased sensors and subsystems. However, they have difficulty to store all channel information in limited memory. In this paper, we suggests and implements an advanced PCM encoder that can efficiently manage memory by minimizing duplicated channel information. This novel PCM encoder allocates duplicated channel information to memory only once. And, sub commutation channels having different information for each minor frame are allocated to the memory by multiples of sub commutation channels. Finally, the suggested PCM encoder was proved by simulation that composed channels of various measurement cycles.

• The KIPS Transactions:PartA
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• v.11A no.4
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• pp.277-284
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• 2004

This paper presents a facial expression control method of 3D avatar that enables the user to select a sequence of facial frames from the facial expression space, whose level of details the user can select hierarchically. Our system creates the facial expression spare from about 2,400 captured facial frames. But because there are too many facial expressions to select from, the user faces difficulty in navigating the space. So, we visualize the space hierarchically. To partition the space into a hierarchy of subspaces, we use fuzzy clustering. In the beginning, the system creates about 11 clusters from the space of 2,400 facial expressions. The cluster centers are displayed on 2D screen and are used as candidate key frames for key frame animation. When the user zooms in (zoom is discrete), it means that the user wants to see mort details. So, the system creates more clusters for the new level of zoom-in. Every time the level of zoom-in increases, the system doubles the number of clusters. The user selects new key frames along the navigation path of the previous level. At the maximum zoom-in, the user completes facial expression control specification. At the maximum, the user can go back to previous level by zooming out, and update the navigation path. We let users use the system to control facial expression of 3D avatar, and evaluate the system based on the results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.58-66
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• 2009

Recently the emerging demands of the light-video encoder promotes lots of research efforts on DVC (Distributed Video Coding). As an appropriate video compression method, DVC has been studied, and Wyner-Ziv (WZ) video compression is its one representative structure. The WZ encoder splits the image into two kinds of frames, one is key frame which is compressed by conventional intra coding, and the other is WZ frame which is encoded by WZ coding. The WZ decoder decodes the key frame first, and estimates the WZ frame using temporal correlation between key frames. Estimated WZ frame (Side Information) cannot be the same as the original WZ frame due to the absence of the WZ frame information at decoder. As a result, the difference between the estimated and original WZ frames are regarded as virtual channel noise. The WZ frame is reconstructed by removing noise in side information. Therefore precise noise estimation produces good performance gain in WZ video compression by improving error correcting capability by channel code. But noise cannot be estimated precisely at WZ decoder unless there is good WZ frame information, and generally it is estimated from the difference of corresponding key frames. Also the estimated noise is limited by comparing with frame level noise to reduce the uncertainty of the estimation method. However these methods cannot provide good noise estimation for every frame or each bit plane. In this paper, we propose a noise nodel selection method which chooses a better noise model for each bit plane after generating candidate noise models. Experimental result shows PSNR gain up to 0.8 dB.