• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.835-849
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• 2013

Joint Collaborative Team on Video Coding (JCT-VC), which have founded ISO/IEC MPEG and ITU-T VCEG, has standardized High Efficiency Video Coding (HEVC). Standardization of HEVC has started with purpose of twice or more coding performance compared to H.264/AVC. However, flexible and hierarchical coding block and recursive coding structure are problems to overcome of HEVC standard. Many fast encoding algorithms for reducing computational complexity of HEVC encoder have been proposed. However, it is hard to implement a real-time HEVC encoder only with those fast encoding algorithms. In this paper, for implementation of software-based real-time HEVC encoder, data-level parallelism using SIMD instructions and CPU/GPU multi-threading methods are proposed. And we also proposed appropriate operations and functional modules to apply the proposed methods on HM 10.0 software. Evaluation of the proposed methods implemented on HM 10.0 software showed 20-30fps for $832{\times}480$ sequences and 5-10fps for $1920{\times}1080$ sequences, respectively.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.397-413
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• 2008

In Gaya area, the Boseong kaolin deposits exhibit locally unusual occurrences such as downward enrichment of kaoin minerals, characteristic hydrothermal alterations (illite and stilbite), and phase relations among kaolin minerals in addition to the extensive weathering of anorthositic country rocks. This indicates that the kaolin deposits seem to be genetically formed as a mixed hydrothermal and residual model. The kaolin ores can be divided into five types on the basis of differences in occurrence, mineral composition and characters. These consist of two types of high-grade ores ranging above 80% in grade and low-grade ores as low as less than 80% including feldspar residuals or the peculiar impurity phase of illite-vermiculite-stilbite. Halloysite and kaolinite are mostly coexisted in the Boseong kaolin, and these kaolin minerals exhibit diverse appearances in crystallinity and morphology. Such a diversity in mineral phase and crystallinity seems to be originated from the complexity in genesis. In addition to these diverse characters of the kaolin, its applied-mineralogical characteristics such as chemical composition, thermal properties, whiteness, viscosity, and etc. made it disadvantageous in terms of ore quality.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.1
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• pp.34-41
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• 2002

In the conventional rake receiver structure for the IS-95 CDMA system, each finger has its own time-deskew buffer or FIFO that aligns the multipath signals to the same timing reference in order to combine symbols. This architecture is not a burden to the rake receiver design mainly because of the small number and size of the buffers. However, the number and size of the buffers are significantly increased in the cdma2000 system which adopts multiple carriers and the small spreading gain for a higher rate in data services. In order to decrease the number of buffers, we propose a new model of the time-deskew buffers, which combines the symbols as well as realigns them at the same time. Our architecture reduces the hardware complexity of the buffers by about more than 60% and 70% compared with the conventional one when we consider each rake receiver has three and four independent fingers, respectively. Moreover, the proposed algorithm is very useful not only to the cdma2000 rake receiver but also to the receiver with many fingers in order to increase the BER performance.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.85-94
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• 2005

Display characterization, deriving the relationship between digital input values and the corresponding CIEXYZ tri-stimulus values, is important to reproduce the accurate color in color management system. The relationship can be estimated from the nine channel TRCs(tone response curves) and the result of this characterization method is better than that of using three channel TRCs. However, the inverse display characterization using nine channel TRCs cannot be directly inverted because the CIEXYZ values corresponding to each of RGB values are inseparable. Accordingly, inverse display characterization is usually implemented by the 3D-LUT (look-up table) method. Although the result of 3B-LUT is accurate, creating the 3D-LUT requires a lot of memory space and considerable amount of measurements. Therefore the inverse characterization method is proposed based on the modeling of channel-dependent values and nine channel inverse process based on the GOG(gain, offset gamma) model. The proposed method enhances the accuracy of display characterization and reduces the complexity and the number of measurements data required for accuracy in 3-D LUT.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.671-682
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• 2004

As new and diverse information technologies are being introduced and software complexity is increased, software development cost and efforts are also sharply increased. Component-Based Development (CBD) technology is appealing as a new way to reduce the cost and effort by increasing reusability and maintainability. Component in CBD has variability infernally which enables customization of the component within the specific domain. A component user can easily set up internally variability parts though Required interface which is provided by the component. Enterprise JavaBeans (EJB) is utilized as a commercial standard to implement Java-based components. However, EJB constructs are limited in directly implementing Required interfaces of coarse-grained components［8］. In this paper, we define Required interface and propose interface-storage technique, class-storage technique, interface-generation technique, and Plug -in technique for implementing required interface of component. Interface-storage technique stores variable value in Required interface and class-storage technique take the Bean containg variability as Required interface without modification of component model. Interface-generation technique generates new Bean which takes the role of Required interface for component variability and Plug-in technique sets up component variability that component user plugged-in variable part externally The proposed four techniques conform to the semantics of CBD component interface and enable the implementation of high quality components.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2010-2024
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• 1998

In video coding, it is important to improve the average picture quality as well as to maintain cosistent picture quality between consecutive pictures. In this paper, we propose a distortion-rate estimation method for MPEG-2 video and a forward rate control method, using the proposed estimation result, to be able to obtain the improved and consistent picture quality of CBR (Constant Bit Rate) encoded MPEG-2 video. The proposed distortion-rate estimation enable us to predict the distortion and the bits generated from an encoded picture at a given quantization step size and vice versa. The most attactive features of proposed distortion-rate estimation are its accuracy and low computational complexity enough to be applied to the practical video coding. In addition, the proposed rate control first determined a quantization parameter per frame by following procedure: distortion-rate estimation, target bit allocation, distortion constraint and VBV(Video Buffer Verification) constraint. And then this quantization parameter is applied to the encoding so that improved and consisten picture quality can be obtained. Furthermore the proposed rate control method can solve the error propagation problem caused by scene change or anchor picture degradation by using the B-picture skipping and the guarantee of the minimum bit allocation for the anchor picture. Experimental results, comparing the proposed forward rate control method with TM5 method, show that the proposed method makes more improed and consistent picture quality than TM5.

• Progress in Medical Physics
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• v.13 no.3
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• pp.129-134
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• 2002

The radiosurgery is planned that prescribed dose was irradiated to tumor for obtaining expected remedial value in stereotactic radiosurgery. The planning for many irregular tumor shape requires long computation time and skilled planners. Due to the rapid development in computer power recently, many optimization methods using computer has been proposed, although the practical method is still trial and error type of plan. In this study, many beam variables were considered and many tumor shapes were assumed cylinderical ideal models. Then, beam variables that covered the target within 50％ isodose curve were searched, the result was compared and analysed. The beam variables considered were isocenter separation distance, number of isocenters and collimator size. Dose distributions obtained with these variables were analysed by dose volume histogram(DVH) and dose profile at orthogonal plane. According to the results compared, the use of more isocenters than specified isocenter dosen't improve DVH and dose profile but only increases complexity of plan. The best result of DVH and dose profile are obtainedwhen isocenter separation was 1.0-1.2 in using same number of isocenter.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.140-156
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• 2010

This study aimed to investigate how science teachers perceived major features of the 2007 revised science curriculum and implementing them in classes. The 2007 revised science curriculum included critical features such as creativity, open inquiry, science writing, discussion and STS. In terms of necessity, clarity and complexity of those features for curriculum implementation, teacher perceptions were examined. Particularly with regard to open inquiry assigned 6 class periods per semester as one of the critical features of 2007 revised science curriculum, we asked teachers how they would prepare and implement the technique in their teaching. In results of this study, science teachers agreed on the necessity and importance of those major features of the 2007 revised science curriculum, including creativity, open inquiry, science writing, discussion, and STS. However, they were not clear on how those would work in their classrooms and expected various impediments. Open inquiry was specifically perceived as most negative in its implementation with the mention of various complex reasons. Based on findings in this study, we proposed the 'Dual Action Research Model' for curriculum implementation. It tries to explain how curriculum is implemented in classrooms and diminish the gaps between curriculum developers and teacher users by means of leading teachers to understand the curriculum meaningfully and implement their teaching based on this understanding.

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.39-52
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• 2012

Surface-subsurface interactions are an intrinsic component of the hydrologic response within a watershed. In general, these interactions are considered to be one of the most difficult areas of the discipline, particularly for the modeler who intends simulate the dynamic relations between these two major domains of the hydrological cycle. In essence, one major complexity is the spatial and temporal variations in the dynamically interacting system behavior. The proper simulation of these variations requires the need for providing an appropriate coupling mechanism between the surface and subsurface components of the system. In this study, an approach for modelling surface-subsurface flow and transport in a fully intergrated way is presented. The model uses the 2-dimensional diffusion wave equation for sheet surface water flow, and the Boussinesq equation with the Darcy's law and Dupuit-Forchheimer's assumption for variably saturated subsurface water flow. The coupled system of equations governing surface and subsurface flows is discretized using the finite volume method with central differencing in space and the Crank-Nicolson method in time. The interactions between surface and subsurface flows are considered mass balance based on the continuity conditions of pressure head and exchange flux. The major module consists of four sub-module (SUBFA, SFA, IA and NS module) is developed.

• Proceedings of the Korea Database Society Conference
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• 1998.09a
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• pp.525-543
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• 1998

This paper proposes a conceptual taxonomy of architectures far workflow management systems. The systematic classification work is based on a framework for workflow architectures. The framework, consisting of generic-level, conceptual-level and implementation-level architectures, provides common architectural principles for designing a workflow management system. We define the taxonomy by considering the possibilities for centralization or distribution of data, control, and execution. That is, we take into account three criteria. How are the major components of a workflow model and system, like activities, roles, actors, and workcases, concretized in workflow architecture？ Which of the components is represented as software modules of the workflow architecture？ And how are they configured and operating in the architecture？ The workflow components might be embodied, as active (processes or threads) modules or as passive (data) modules, in the software architecture of a workflow management system. One or combinations of the components might become software modules in the software architecture. Finally, they might be centralized or distributed. The distribution of the components should be broken into three: Vertically, Horizontally and Fully distributed. Through the combination of these aspects, we can conceptually generate about 64 software Architectures for a workflow management system. That is, it should be possible to comprehend and characterize all kinds of software architectures for workflow management systems including the current existing systems as well as future systems. We believe that this taxonomy is a significant contribution because it adds clarity, completeness, and "global perspective" to workflow architectural discussions. The vocabulary suggested here includes workflow levels and aspects, allowing very different architectures to be discussed, compared, and contrasted. Added clarity is obtained because similar architectures from different vendors that used different terminology and techniques can now be seen to be identical at the higher level. Much of the complexity can be removed by thinking of workflow systems. Therefore, it is used to categorize existing workflow architectures and suggest a plethora of new workflow architectures. Finally, the taxonomy can be used for sorting out gems and stones amongst the architectures possibly generated. Thus, it might be a guideline not only for characterizing the existing workflow management systems, but also for solving the long-term and short-term architectural research issues, such as dynamic changes in workflow, transactional workflow, dynamically evolving workflow, large-scale workflow, etc., that have been proposed in the literature.