• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3916-3936
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• 2014

Smartphone applications like games, image processing, e-commerce and social networking are gaining exponential growth, with the ubiquity of cellular services. This demands increased computational power and storage from mobile devices with a sufficiently high bandwidth for mobile internet service. But mobile nodes are highly constrained in the processing and storage, along with the battery power, which further restrains their dependability. Adopting the unlimited storage and computing power offered by cloud servers, it is possible to overcome and turn these issues into a favorable opportunity for the growth of mobile cloud computing. As the mobile internet data traffic is predicted to grow at the rate of around 65 percent yearly, even advanced services like 3G and 4G for mobile communication will fail to accommodate such exponential growth of data. On the other hand, developers extend popular applications with high end graphics leading to smart phones, manufactured with multicore processors and graphics processing units making them unaffordable. Therefore, to address the need of resource constrained mobile nodes and bandwidth constrained cellular networks, the computations can be migrated to resourceful servers connected to cloud. The server now acts as a bridge that should enable the participating mobile nodes to offload their computations through Wi-Fi directly to the virtualized server. Our proposed model enables an on-demand service offloading with a decision support system that identifies the capabilities of the client's hardware and software resources in judging the requirements for offloading. Further, the node's location, context and security capabilities are estimated to facilitate adaptive migration.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.727-736
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• 2009

In this paper, the $arccos(cos^{-1})$ arithmetic unit for mobile graphics accelerator is designed. The mobile vector graphics applications need tight area, execution time, power dissipation, and accuracy constraints compared to desktop PC applications. The designed processor adopts 2nd-order polynomial approximation scheme based on IEEE floating point data format to satisfy speed and accuracy conditions and reduces area via hardware sharing structure. The arccosine processor consists of 15,280 gates and its estimated operating frequency is about 125Mhz at operating condition of $0.35{\mu}m$ CMOS technology. Because the processor can execute arccosine function within 7 clock cycles, it has about 17 MOPS(million arccos operations per second) execution rate and can be applicable to mobile OpenVG processor. And because of its flexible architecture, it can be applicable to the various transcendental functions such as exponential, trigonometric and logarithmic functions via replacement of ROM and minor hardware modification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.321-324
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• 2010

There have been lots of researches on a multi-core processor. The enhancement has been performed through parallelization method. Multi-core architecture in the mobile environment has emerged. But, there is a limit to a mobile CPU's performance. GP-GPU(General-Purpose computing on Graphics Processing Units) can improve performance without adding other dedicated hardware. This paper presents the implementation of Inverse Quantization, Inverse DCT and Color Space Conversion module in H.264/AVC decoder using Multi-Core GP-GPU for a mobile environments. The proposed architecture improves approximately 50% of performance when it use all the features.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.677-687
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• 2009

Despite the fact that the mobile environment has favorable conditions for using data contents, it is not easy to implement enhanced data services for mobile broadcasting based on MPEG-4 BIFS. With a structure inherited from VRML, BIFS targets different types of content with a development approach that is not very compatible with broadcasting contents. Furthermore, it is not easy to implement BIFS because the standard is too complicated for the mobile broadcasting environment. Accordingly, this study proposes an enhanced mobile TV contents model that provides interactive 3D objects and GUI for the viewers to interact with the broadcasting contents. By applying the model to the DMB environment, this study suggests a direction for future developments of mobile broadcasting contents. In order to represent 3D graphics on mobile TV, we analyzed MPEG-BIFS 3D nodes and composed a subset of VRML profile, and defined new nodes that can efficiently represent GUI at the content development level. If this study helps facilitate expression of 3D graphics and interactions in data contents composition, enhanced efficiency of contents development is expected to promote the development of various contents suitable for the mobile broadcasting environment.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.38-42
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• 2008

In the 2000s, the PC package game market has withered, but the internet based on-line game, the wireless internet based mobile game and high-powered console game market have been main stream. Among those markets, mobile game market has rapidly increased because it has 'mobility' that overcomes the limitation of time and area. But, unlike other platforms, mobile game user have to pay the higher price for download mobile game contents through the wireless internet and mobile game developer have to overcome the limitation of storage memory capacity.of mobile phone. Chiefly, the image data consume the storage capacity of mobile game contents, this paper present a technology to optimize image data for mobile game contents through analyzing type of compression method and image formats.

• Journal of Korea Game Society
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• v.6 no.4
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• pp.63-70
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• 2006

This paper studied various low power structures of texture caches for mobile 3D graphics accelerator to reduce the memory latency of texture data. Also the paper designed the texture cache with the variable threshold values of power mode transition according to the filtering algorithms. In the trace driven simulation, we compared the performance of those structures using Quake game engine as the benchmark. Also the algorithm was proposed and verified by the simulation, which has variable threshold values of power mode transitions according to the selected texture filtering method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.23-32
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• 2007

This paper proposes a reconfigurable parallel processor architecture which can efficiently implement various multimedia applications, such as 3D graphics, H.264/H.263/MPEG-4, JPEG/JPEG2000, and MP3. The proposed architecture directly connects memories and processors so that memory access time and power consumption are reduced. It supports floating-point operations needed in the geometry stage of 3D graphics. It adopts partitioned SIMD to reduce hardware costs. Conditional execution of instructions is used for easy development of parallel algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1891-1898
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• 2013

To efficiently execute 3D graphic APIs, such as OpenGL and Direct3D, special purpose arithmetic unit(SFU) which supports floating-point sine, cosine, reciprocal, inverse square root, base-two exponential, and logarithmic operations is designed. The SFU uses second order minimax approximation method and lookup table method to satisfy both error less than 2 ulp(unit in the last place) and high speed operation. The designed circuit has about 2.3-ns delay time under 65nm CMOS standard cell library and consists of about 23,300 gates. Due to its maximum performance of 400 MFLOPS and high accuracy, it can be efficiently applicable to mobile 3D graphics application.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.541-542
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• 2008

We propose an architecture for a lighting engine for mobile 3D graphics. The proposed architecture has a variable pipeline depending on lighting effects and the number of lighting sources so that unnecessary operations and power consumption are minimized. We design a lighting engine basedon the proposed architecture using Verilog-HDL and synthesized it using a 0.25um CMOS standard cell library at 100MHz. The synthesis results show that it occupies 180,000 and 260,000 gates for 24bit and 32bit formats, respectively.

• Journal of Internet Computing and Services
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• v.6 no.5
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• pp.97-110
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• 2005

Recently, many WMS(Web Map Services) and POI(Point of Interest) services come to be in service on the Internet using Web GIS(Geographic Information System) as Information Technology and computer H/W are evolved faster in its speed, network bandwidth and features. The Web GIS is, however, limited and constrained on the specification of its system configuration, the service class provided and the presentation methodology of a map. As the mobile Internet becomes popular in mobile service, Web GIS service on mobile environment is strongly required and to be provided by location based WMS(Web Map Service) on a mobile client such as PDA with location information of the user. In this paper, we made an effort to design and implement a GIS computing environment by thin client for mobile web map service. For implementing the thin client GIS computing environment. we were using NGII's(National Geographic Information Institute's) DXF map, representing the map by SVG(Scalable Vector Graphics) recommended by OGC(OpenGis Consortium), and adapting standard XML web service to provide the thin client GIS service on PDA by applying the location information of the user in realtime with GPS on mobile environment.