• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.123-126
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• 2007

This paper presents the SVC (Scalable Video Coding) scheme which enables the AT-DMB (Advanced Terrestrial - DMB) video service in enhancement layer, while keeping the current T-DMB video service in base layer. But, it is very complicate to implement the SVC encoder and so it is necessary to analyze the complexity and performance for SVC encoder's structures and coding parameters. In this paper, through computer simulations, SVC coding parameters are tested and then, based on these results, three types of SVC encoder models are compared from the viewpoint of the complexity and performance.

• Journal of Korea Water Resources Association
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• 제33권3호
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• pp.331-340
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• 2000

This study aims to develop a methodology of real time forecasting of mundation risk based on DAMBRK model and Kalman filter. The model is based on implicit, nonlinear finite difference approximatIons of the one-dimensional dynamic wave equations. The stochastic estimator uses on extended Kalman filter to provide optimal updating estimates. These are accomplished by combining the predictions of the determurustic model with real time observauons modified by the Kalman filter gain ractor. Inundation risks are also estimated by applying Monte Carlo simulation to consider the variability in cross section geometry and Manning's roughness coefficient. The model calibrated by applying to the floods ot South Han River on September, 1990 and August, 1995. The Kalman tilter model indicates that significant improvement compared to deteriministic analysis in flood routing predictions in the river. Overtopping risk of levee is also presented by comparing levee height with simulated flood level. level.

• Journal of Korea Water Resources Association
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• 제34권3호
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• pp.241-251
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• 2001

A flow determination algorithm is proposed for the distributed hydrologic model. The advantages of a single flow direction scheme and multiple flow direction schemes are selectively considered to address the drawbacks of existing algorithms. A spatially varied flow apportioning factor is introduced in order to accommodate the accumulated area from upslope cells. The channel initiation threshold area(CIT) concept is expanded and integrated into the spatially distributed flow apportioning algorithm in order to delineate a realistic channel network. An application of a field example suggests that the linearly distributed flow apportioning scheme provides some advantages over existing approaches, such as the relaxation of over-dissipation problems near channel cells, the connectivity feature of river cells, the continuity of saturated areas and the negligence of the optimization of few parameters in existing algorithms. The effects of grid sizes are explored spatially as well as statistically.

• Journal of the Korean Geographical Society
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• 제42권1호
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• pp.1-14
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• 2007

This study aimed to evaluate weather forecast accuracies of minimum temperature, maximum temperature, precipitation and sky cover by the localized land forecast areas over South Korea Average forecast accuracy score of precipitation was the lowest while that of sky cover was the highest during the study period Overall forecast accuracy scores for Gangwon-do was the lowest while those for Gyeongsangnam-do and Gyeongsangbuk-do were higher than other areas. The frequencies of perfect forecast(eight points) by seasons, were the highest during winter and the lowest during summer. pressure pattern analyses for days when forecast accuracy scores were poor, showed that precipitation forecast accuracy scores were lower due to the movement of the stationary fronts during summers. When continental polar air masses expanded, forecast accuracy of temperature became greatly lower during autumns and winters As the migratory anticyclone pattern rapidly moved, forecast accuracy became lower during springs and autumns. Forecast accuracies were compared by wind directions at 850hPa for the Young-dong region where forecast accuracy was the lowest. Forecast accuracy scores on minimum and maximum temperatures were low when winds were westerlies and forecast accuracy scores of precipitation were low when winds were easterlies.

• KIISE Transactions on Computing Practices
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• 제21권3호
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• pp.173-182
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• 2015

Motion control systems are widely deployed in various industrial automation processes. The motion controller, which is a key element of motion control systems, has stringent real-time constraints. The controller must provide a short and deterministic control message transmission cycle, and minimize the actuation deviation among motor drives. To meet these requirements, hardware-based proprietary controllers have been prevalent. However, since it is becoming difficult for such an approach to meet increasing needs of system interoperability and scalability, nowadays, software-based universal motion controllers are regarded as their substitutes. Recently, embedded motion controller solutions are gaining attention due to low cost and relatively high performance. In this paper, we designed and implemented an embedded motion controller on an ARM-based evaluation board by using Xenomai real-time kernel and other open source software components. We also measured and analyzed the performance of our embedded controller under a realistic test-bed environment. The experimental results show that our embedded motion controller can provide relatively deterministic performance with synchronized control of three motor axis at 2 ms control cycle.

• Journal of KIISE:Software and Applications
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• 제28권12호
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• pp.885-895
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• 2001

Existing system analysis models suggest various ideas to present entity relations and event flows for consistency between analysis and design paradigms. However, they are preferred to derive and arrange related entities on system flow than to identify entities. To identify entities systematically is a basic and important work of software development, and identified entities can be major assets of business system. In case of business systems the business rules or the computed or derived information like attendance lists of lecture system can be the most important system assets. The management information or meta data are also. In this paper, we suggest a business system analysis models to derive and present entities. System is identified entities, interfaces and event or behaviors through this model then entities are extended to independent entities, dependent entities, which are dependent to independent entities, constraint shows the physical and administrative notices. Various entity identification can reduce the incompleteness of entity analysis.

• Journal of Korea Game Society
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• 제11권6호
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• pp.115-125
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• 2011

Recently, a sharp increases of users of smartphone is not only cause an rapid growth smartphone-games market, but also secured it's position as a high value market. thus have to begets a multilateral study to the smartphone of newly-rising. however the earlier studies were researched previous smartphone, despite extended research is needed for smartphone-games. therefore the study's purpose is to draw a main factors it has a decisive effect for recommendation and sustainable-usage through recognizing the cause-and-effect relationship with purchase intention, purchase action, satisfaction, recommendation, and sustainable usage that based purchase-effect-factors of smartphone-games. for this study the questionnaire of 293 was taken. and structural equation model was adopted to analyze this study.

• Journal of KIISE:Software and Applications
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• 제31권7호
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• pp.883-900
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• 2004

As object-oriented development technology that increases extensibility and reusability has been widely spread, it can shorten development period and enhance quality by reusing verified object-oriented artifacts. Thus we can construct high quality component-based system at short time transforming component-based model using verified object-oriented artifacts. In this paper, we propose techniques to transform available object-oriented design model into component-based model using formal specification techniques in order to increase accuracy of transformation. First, formal specification language for component is defined for formal specification of component-based design. And, techniques for formal specification of object-oriented design using Object-Z, a formal specification language, is proposed in structural, functional, and dynamic aspects. Next, we present techniques for transforming formal specification of object-oriented design into formal specification of component-based design. Through a case study we apply the proposed transformation techniques and show the transformation process of object-oriented formal specification into component-based formal specification.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제38권3호
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• pp.217-227
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• 1989

A process control graphic system is proposed as an efficient tool for monitoring the operation of power plant. It uses the multi-processor structure with 60 Kbyte shared memory as an implemental type of the distributed computer system, so that it is flexible, functionally extensible, and applicable to real-time process. The shared memory is used as a real-time database handling the process values and operator's commands. The database files, generated by the user-interactive graphic editor developed for the system or text editor, have the characteristics of simplicity and user-friendliness. The process control graphic system, that can monitor the operation of boiler and function as a backup controller in case of failure in boiler controller, is applied to Ulsan power plant. As a result, it displays the operating data of the boiler process without error by 14 pages of color graphic image according to the operation menu, and additionally functions well as a fault-tolerant control system.

• Archives of design research
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• 제19권2호
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• pp.333-342
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• 2006

Consumers have paid attention to various functions of PC's nowadays from its efficiency in the past. This study set limits to adapted computers by consumer needs for their residence facilities and ubiquitous environment in our society. The purpose of this study is to suggest high potentialities of adapted computers and it's design for materializing house ubiquitous system. It has come out from analyzing PC market. The result is that Barebone PC, a kind of set PC, could be one of the most actual way for materializing house ubiquitous system. This study suggests many potentialities of Barebone PC which invites modular system. The existing Barebone PC is a kind of semimanufactures, however the new Barebone PC in this study is a expanded concept of modular system that connected to the area of the electric home appliances. This is inspected by analyzing the relation among potentialities and impotance of set PC design and module.