• Journal of Broadcast Engineering
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• v.12 no.1 s.34
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• pp.11-27
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• 2007

T-DMB(Terrestrial-Digital Multimedia Broadcasting) for portable and mobile broadcasting service was officially launched in the metropolitan area of Korea in December 2005. The development of interactive data services and the expansion of T-DMB network have been now progressed, and the regional T-DMB broadcasters will be selected in the near future. Although it is important to evaluate service area and reduce a fringe area for optimizing RF coverage of T-DMB, there was no professional system to support those works, and therefore lots of resources in budget, manpower and time were required. The measurement considering characteristics of SFN(Single Frequency Network) is essential in the implementation of T-DMB network which needs to control synchronization, spacing and output power of transmitters. In addition, mobile measurement, enough measured parameters for many-sided analysis of reception quality, efficient management of enormous measured data and representation of measured results on the electronic map are also important in evaluating service area. In this paper, we derived requirements for a new measurement system in T-DMB by considering the above details, and we proposed and developed an integrated measurement and analysis system. The developed system was applied to the implementation of T-DMB network of KBS and field tests, and it proved its efficiency and accuracy in result.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.185-190
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• 2006

휴대폰 산업의 발전과 더불어 발전해온 휴대폰 서비스는 최근 단순한 정보 제공을 넘어 생활에 중요한 도구로 활용되는 모습을 보인다. 최근 등장하는 휴대폰 서비스는 종류가 다양하고 최신 휴대폰과 결합되어 복잡해져 사용자로 하여금 필요한 서비스를 선택하여 조작하는 것까지 전반적인 사용 과정의 어려움을 가져왔다. 더군다나 휴대폰 서비스는 무형의 상품이기 때문에 직접 조작해보지 못하고 사용해야 하며, 이것은 사람들로 하여금 불안감을 갖도록 한다. 따라서, 본 연구에서는 휴대폰 서비스에 대한 불안감을 줄이고 사용을 확장시키는 방법으로 서비스를 직접 만지고 조작해볼 수 있는 사전 체험을 제안하며, 이를 위한 도구로 웹사이트를 활용하는 방안을 제안한다. 웹사이트는 상호작용적인 매체로써 자연스럽게 사용자가 참여하고 개입하도록 유도하는 매체이며, 다양한 시각적, 청각적 미디어를 활용할 수 있어 감각적 체험을 제공하는데 유리하다. 또한 다른 매체와 비교해 웹사이트는 공간적, 시간적 제약이 적어 많은 사람들이 원하는 시간에 접근하도록 한다. 또한 이성과 감성적인 정보를 통합적으로 처리하는 인간의 특성을 고려해 볼 때, 정보와 재미를 함께 제공할 수 있는 웹사이트의 특성은 효과적이라 볼 수 있다. 마케팅 측면에서 보더라도 저렴한 비용으로 많은 사람들에게 정보를 전달할 수 있고, 사용자들의 행동을 측정해 데이터베이스화 한 후 후에 활용할 수 있다. 이러한 점들을 통합해보면 웹사이트는 휴대폰 서비스를 체험해보도록 하는 공간으로 적합하다고 볼 수 있다. 웹사이트에서 가상 체험을 효과적으로 활용하기 위해서 사용자들의 체험 과정에 어떠한 요인이 영향을 미치는지 알 필요가 있다. 이를 위해 본 연구에서는 현재 휴대폰 서비스 체험 사이트들의 체험 제공 방식을 분석해 유형을 나눈 후에 사용자 조사를 통해 사용자들에게 선호되는 방식과 체험 과정에 영향을 미친 요인을 고찰한다. 그리고 최종적으로 이러한 요인이 실제 휴대폰 서비스에 대한 호감과 어떤 관계를 갖는지 알아본다. 본 연구에서는 이를 위해 최근 가장 높은 이용률을 보이고 있는 20,30대 휴대폰 서비스 사용자 100명을 대상으로 2005년 10월 20일~30일에 설문조사와 간단한 인터뷰를 실시하여 선호 유형과 체험에 영향을 미치는 요인을 도출하였으며, 서비스 호감과의 관계를 알기 위해 이 중 가장 관여도가 높았던 17명을 대상으로 2005년 11월 10일~15일에 심층 인터뷰를 실시하였다. 사용자 조사 결과, 분류된 유형 중 체험방식에서는 개입의 정도가 클수록, 사용상황 안내방식에서는 가상공간과 메뉴로 제공하는 방식을, 사용방법 안내형식에서는 휴대폰 전체 이미지를, 마지막으로 표현형식에서는 일러스트레이션과 영상을 가장 선호하는 것으로 나타났다. 체험에 영향을 미치는 요인은 체험적 측면,정보제공 측면,웹사이트의 측면으로 구분되었으며 휴대폰 서비스의 호감과의 관계에서는 체험적 측면과 정보제공 측면은 서비스에 대한 호감과 깊은 관계를 갖고 있는 것으로 나타난 반면에 웹사이트의 측면은 서비스와 직접적인 관련을 짓지 않는 것으로 나타났다.

• Journal of Broadcast Engineering
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• v.15 no.5
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• pp.653-664
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• 2010

Generally existing video codec employs entropy coding to deal with residual signals with considering temporal and spatial properties. Scalable Video Coding(SVC) which is extension of H.264/AVC has three technical concepts for removing redundancies between inter-layers. In spite of using novel prediction method between inter-layers in SVC, it is still using same entropy coding method to residual signals. According to the studies, the residual obtained by inter-layer prediction technique has different features of residual signal acquired by spatial or temporal prediction technique. In this paper, we propose an efficient entropy coding method which codes the residual signal obtained by inter-layer prediction with regarding its features adequately. We re-designed the Coded Block Pattern(CBP) table suitably for inter-layer texture prediction. The experiments show that the proposed method can further reduce the BD-Bitrate up to average 2.20% in 4CIF and 1.14% in CIF resolution compared to the existing JSVM 9.18.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.439-447
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• 2011

In this paper, we present a novel method to use metadata based on the eXtensible Markup Language (XML) for efficient data transfer between visual effects (VFX) and film editing. For transferring data to the VFX process, image sequences such as Cineon DPX or TGA are currently used in Korean post productions. The use of image sequences tends to increase rendering time and the amount of data for repetitive file format conversions, and as a result causes inefficiency in the entire production process. On the other hand, the use of metadata on the XML can reduce time and data because the repetitive rendering processes are not needed. This method can also be used at a variety of editing and VFX programs, and provides content information for combining online contents. The development of XML-base methods on the web enables flexible combination with other types of media.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.839-846
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• 2006

Context-aware adaptive service for overcoming the limitations of wireless devices and maintaining adequate service levels in changing environments is becoming an important issue. However, most existing studies concentrate on an adaptation module on the client, proxy, or server. These existing studies thus suffer from the problem of having the workload concentrated on a single system when the number of users increases md, and as a result, increases the response time to a user's request. Therefore, in this paper the adaptation module is dispersed and arranged over the client, proxy, and server. The module monitors the contort of the system and creates a proposition as to the dispersed adaptation system in which the most adequate system for conducting operations. Through this method faster adaptation work will be made possible even when the numbers of users increase, and more stable system operation is made possible as the workload is divided. In order to evaluate the proposed system, a prototype is constructed and dispersed operations are tested using multimedia based learning content, simulating server overload and compared the response times and system stability with the existing server based adaptation method. The effectiveness of the system is confirmed through this results.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.453-463
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• 2002

With the prevalence of multi-dimensional data such as images, content-based retrieval of data is becoming increasingly important. To handle multi-dimensional data, multi-dimensional index structures such as the R-tree, Rr-tree, TV-tree, and MVP-tree have been proposed. Numerous research results on how to effectively manipulate these structures have been presented during the last decade. Query processing strategies, which is important for reducing the processing time, is one such area of research. In this paper, we propose query processing algorithms for R-tree based structures. The novel aspect of these algorithms is that they make use of the notion of VP filtering, a concept borrowed from the MVP-tree. The filtering notion allows for delaying of computational overhead until absolutely necessary. By so doing, we attain considerable performance benefits while paying insignificant overhead during the construction of the index structure. We implemented our algorithms and carried out experiments to demonstrate the capability and usefulness of our method. Both for range query and incremental query, for all dimensional index trees, the response time using VP filtering was always shorter than without VP filtering. We quantitatively showed that VP filtering is closely related with the response time of the query.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.859-871
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• 2013

In this paper, we propose an algorithm that generates multi-view images by grid-mesh based image domain warping using occlusion mask and various image features obtained from the stereoscopic images. In the proposed algorithm, we first extract image saliency map, line segments and disparity saliency map from stereo images and then get them through a process that improves the quality of extracted features. This process is accomplished in two steps. In the first step, reliability of disparity saliency map on object boundary regions is enhanced by using occlusion information. And in the second step, we enhance the quality of image features in terms of temporal consistency by using temporal consistency information for stereo images. With these enhanced features, multi-view images are generated by grid-mesh based image domain warping technique. Experimental results show that the proposed algorithm performs better than existing algorithms in terms of visual quality.

• Journal of Broadcast Engineering
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• v.27 no.3
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• pp.391-401
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• 2022

As deep learning-based object detection and recognition research have been developed recently, the scope of application to industry and real life is expanding. But deep learning-based systems in the construction system are still much less studied. Calculating materials in the construction system is still manual, so it is a reality that transactions of wrong volumn calculation are generated due to a lot of time required and difficulty in accurate accumulation. A fast and accurate automatic drawing recognition system is required to solve this problem. Therefore, we propose an AI-based automatic drawing recognition accumulation system that detects and recognizes steel materials in construction drawings. To accurately detect steel materials in construction drawings, we propose data augmentation techniques and spatial attention modules for improving small object detection performance based on YOLOv4. The detected steel material area is recognized by text, and the number of steel materials is integrated based on the predicted characters. Experimental results show that the proposed method increases the accuracy and precision by 1.8% and 16%, respectively, compared with the conventional YOLOv4. As for the proposed method, Precision performance was 0.938. The recall was 1. Average Precision AP_0.5 was 99.4% and AP_0.5:0.95 was 67%. Accuracy for character recognition obtained 99.9.% by configuring and learning a suitable dataset that contains fonts used in construction drawings compared to the 75.6% using the existing dataset. The average time required per image was 0.013 seconds in the detection, 0.65 seconds in character recognition, and 0.16 seconds in the accumulation, resulting in 0.84 seconds.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.

• Journal of Broadcast Engineering
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• v.12 no.4
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• pp.360-372
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• 2007

We propose a fast inter-layer mode decision method by utilizing coding information of base layer upward its enhancement layer inscalable video coding (SVC), also called MPEG-4 part 10 Advanced Video Coding Amendment 3 or H.264 Scalable Extension (SE) which is being standardized. In this paper, when the motion vectors from the base layer have zero motion (0, 0) in inter-layer motion prediction or the Integer Transform coefficients of the residual between current MB and the motion compensated MB by the predicted motion vectors from the base layer are all zero, the block mode of the corresponding block to be encoded at the enhancement layer is determined to be the $16{\times}16$ mode. In addition, if the predicted mode of the MB to be encoded at the enhancement layer is not equal to the $16{\times}16$ mode, then the rate-distortion optimization is only performed on the reduced candidated modes which are same or smaller partitioned modes. Our proposed method exhibits the complexity reduction in encoding time up to 72%. Nevertheless, it shows negligible PSNR degradation and bit rate increase up to 0.25dB and 1.73%, respectively.