• Journal of Korea Multimedia Society
• /
• v.9 no.7
• /
• pp.864-871
• /
• 2006

With the advancement of the digital broadcasting and popularity of Internet, there is an increasing demand for digital data. Recently, several studies have been made on the digital watermarking for copyright protection of digital data. We propose a blind video watermarking using minimum modification of motion vectors. Conventional methods based on motion vectors do watermarking using modification of motion vectors. However, change of motion vectors results in the degradation of video quality. Thus, our proposed algorithm minimizes modification of the original motion vectors to avoid degradation of video quality using simple embedded conditions. Besides, our scheme guarantees the amount of embedded watermark data using the adaptive threshold considering the human visual characteristic. In addition, this is compatible with current video compression standards without changing the bitstream. Experimental result shows that the proposed scheme obtains better video quality than other previous algorithms by about $0.5{\sim}1.0\;dB$.

• Journal of KIISE
• /
• v.43 no.8
• /
• pp.841-847
• /
• 2016

As network technology advances, a larger number of devices are connected through the Internet. Recently, cloud storage services are gaining popularity, as they are convenient to access anytime and anywhere. Among cloud storage services, object storage is the representative one due to their characteristics of low cost, high availability, and high durability. One limitation of object storage services is that they can access data on the cloud only through the HTTP-based RESTful APIs. In our work, we resolve this limitation with the in-memory file system which provides a POSIX interface to the file system users and communicates with cloud object storages with RESTful APIs. In particular, our flush mechanism is compatible with existing file systems, as it is based on the swap mechanism of the Linux kernel. Our in-memory file system backed by cloud storage reduces the performance overheads and shows a better performance than S3QL by 57% in write operations. It also shows a comparable performance to tmpfs in read operations.

• The KIPS Transactions:PartD
• /
• v.10D no.6
• /
• pp.873-884
• /
• 2003

So far, significant achievements have been studied on the development of models for spatial and spatiotemporal objects with indeterminate boundaries which are found in many applications for geographic analysis and image understanding. Therefore, in this paper we propose the spatiotemporal data model which is applicable for spatial and spatiotemporal objects with uncertainty. Based on this model, we defined topological relationships among the indeterminate spatiotemporal objects and designed the algorithm for the operations. For compatibility with existing spatial models, the proposed model has been designed by extending the spatiotemporal object model which is based on the open GIS specification. We defined indeterminate spatial objects, such as the objects whose position and the shape change discretely over time, and the objects whose shape changes continuously as well as the position. We defined topological relationships among these objects using the extended 9-IM. The proposed model can be efficiently applied to the management systems of natural resource data, westher information, geographic information. and so on.

• Journal of Digital Convergence
• /
• v.17 no.8
• /
• pp.149-157
• /
• 2019

This study analyzed the impact of various factors on the use-diffusion of smart speakers. 300 survey responses of Chinese consumers were analyzed using structured models. The results show that both autonomy and adaptability had significant impacts on perceived usefulness and perceived easy of use. Multifunctionality and ability to cooperate affected perceived usefulness, while reactivity did not affected perceived usefulness or perceived easy of use. Anthropomorphism increased perceived enjoyment. Both perceived usefulness and perceived easy of use have been identified to improve the use-diffusion of smart speakers. Perceived enjoyment enhanced the variety of use. We expect these results help understand the factors that need to be considered for the design or marketing communication of smart products.

• Journal of the Society of Disaster Information
• /
• v.17 no.1
• /
• pp.25-38
• /
• 2021

Purpose: To reduce the damage caused by continuously occurring typhoons, we proposed a standardized grid so that it could be actively utilized in the prevention and preparation stage of typhoon response. We established grid-based convergence information on the typhoon risk area so that we showed the effectiveness of information used in disaster response. Method: To generate convergent information on typhoon hazard areas that can be useful in responding to typhoon situation, we used various types of data such as vector and raster to establish typhoon hazard area small grid-based information. A standardized grid model was applied for compatibility with already produced information and for compatibility of grid information generated by each local government. Result: By applying the grid system of National branch license plates, a grid of typhoon risk areas in Seoul was constructed that can be usefully used when responding to typhoon situations. The grid system of National branch license plates defines the grid size of a multi-dimensional hierarchical structure. And a grid of typhoon risk areas in Seoul was constructed using grids of 100m and 1,000m. Conclusion: Using real-time 5km resolution grid based weather information provided by Korea Meteorological Administration, in the future, it is possible to derive near-future typhoon hazard areas according to typhoon travel route prediction. In addition, the national branch number grid system can be expanded to global grid systems for global response to various disasters.

• Journal of Internet Computing and Services
• /
• v.25 no.4
• /
• pp.109-119
• /
• 2024

This study aims to contribute to the initial research on on-device AI in an environment where generative AI-based services on mobile and other on-device platforms are increasing. To derive success strategies for generative AI-based chatbot services in a mobile environment, over 200,000 actual user experience review data collected from the Google Play Store were analyzed using the LDA topic modeling technique. Interpreting the derived topics based on the Information System Success Model (ISSM), the topics such as tutoring, limitation of response, and hallucination and outdated informaiton were linked to information quality; multimodal service, quality of response, and issues of device interoperability were linked to system quality; inter-device compatibility, utility of the service, quality of premium services, and challenges in account were linked to service quality; and finally, creative collaboration was linked to net benefits. Humanization of generative AI emerged as a new experience factor not explained by the existing model. By explaining specific positive and negative experience dimensions from the user's perspective based on theory, this study suggests directions for future related research and provides strategic insights for companies to improve and supplement their services for successful business operations.

• The KIPS Transactions:PartD
• /
• v.11D no.5
• /
• pp.1197-1204
• /
• 2004

Rights process problem was stated among actors that participated in digital contents distribution while it was various type of digital content service. In order to solve it, It was expressed conceptual and technical elements by reflecting a system. Among them, the interoperability of metadata became a important issue. As for the metadata for contents service, necessity about standardization is stated as a basic framework composing a service system. This paper proposed the metadata element which focus on the rights process that is being a key factor of a DRM(Digital Right Management) system for digital comics contents service. Therefore, it was verified by using Context Model of MPEG-21 RDD with interoperability between metadata elements which developed a XML format and the existing MPEG-21 RDD elements. The study results will become basic materials in the system design that considered metadata element development and interoperability of digital contents of other field

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.1
• /
• pp.159-164
• /
• 2013

Recently the solution integrated of vision and motion controller which are important element in automatiomn system has been many developed. However typically such a solutions has a many case that integrated vision processing and motion control into network or organized two chip solution on one module. We implement one chip solution integrated into vision and motion controller using Zynq-7000 that is developed recently as extended processing platform. We also apply EtherCAT to motion control that is industrial Ethernet protocol which have compatibility for open standardization Ethernet in order to control of motion because EtherCAT has a secure to realtime control and can treat massive data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.11a
• /
• pp.298-301
• /
• 2010

최근 전자업계의 중요한 화두 중 하나는 3D이다. 3D 입체 영상 기술은 미디어 환경을 변화시키고, 이에 발맞춰 방송환경 또한 변하고 있다. 고화질 3D 입체 방송은 기존의 2D 방송 서비스와 호환성을 유지하면서 시간적으로 2D 프로그램과 3D 프로그램이 혼용되어 제공되는 입체 방송 서비스가 될 것이다. 기존의 2D 기반 디지털 방송 서비스 환경에서 고화질 3D 입체 방송을 할 수 없다. 현재 국제 표준기구인 MPEG에서는 3D 서비스 방안으로 ISO/IEC 23002-3(MPEG-C part.3)이 표준화되었다. MPEG-C part.3에서 부가데이터인 depth map과 parallax map을 사용한다. 하지만 공간 주파수가 높은 영상의 depth map과 parallax map은 객체의 경계가 확실하지 않아 3D 입체 구현 시 객체의 경계면이 뭉개질 수 있다. 따라서 본 논문은 고화질 3D 입체 방송 서비스를 위한 전송 방안을 제시하고 있으며, MPEG-C part.3를 이용한 스테레오스코픽 영상 전송방안에 대해 소개한다.

• The KIPS Transactions:PartD
• /
• v.11D no.1
• /
• pp.1-10
• /
• 2004

According to the evolution of the Internet and wireless mobile communication technology, techniques for mobile databases and wireless web services are issued for them. Recently, these changes of geographic application environment increase the needs for development of new GIS database system for the web services and embedded system. In this paper, we proposed a Jana-based web database systems that can be used in the web-based GIS and mobile databases. This proposed system has been implemented using the Java to be displayed easily into the portable computing devices and Java-based web application servers and using OpenGIS for web data interoperability. Also, it can efficiently process web-based spatial queries by developing a spatial query processor including schema manager and a spatial object storage module.