• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.773-781
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• 2006

XML is a standard language to express and exchange the data over the web. Recently, researches about techniques that storing XML documents into RDBMS and managing it have been progressed. These researches use a technique that are receiving the DTD document as an input and generate the relational schema from it. Existing researches, however, do not consider the semantic preservation because of the simplification of the DTD. Further, because existing studies only focus on the preservation technique to store information such as content and structure, there is a troublesomeness that have to use the stored-procedure or trigger for the data integrity during the stores of XML documents. This paper proposes a improved Inlining technique to create effective relations and to preserve semantics which can be inferred from DTD.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.76-85
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• 2018

The interest in the Building Information Modeling (BIM) technology has risen remarkably due to the effects on construction work period reduction, cost reduction, work safety improvement, and other factors. In civil engineering field, BIM applications mainly focus on data modeling and virtual construction. In this study, we present the BIM-based virtual construction and analyze the effects of BIM for the railway facilities so that the conventional approach to the equipment operation plan can be improved in order to prevent safety accidents which can result from unclear information during the operation plan. The BIM-based virtual construction technology is applied to establish the construction plan for the site with constraints, the installation of steel girder needs to be completed, avoiding interference with the existing high-speed railway operation within a given limited time. A virtual construction model consisting of topography, structures, equipments, and avatar was built and more detailed model, including safety guard rails, was then created. Specifications of the construction equipment were input as a database, and the virtual construction model was manipulated in the equipment operation planning. Through the BIM-based virtual construction, including the verification of alternative construction method, 311 million won was saved and the construction period was shortened by 87 days compared to the original plan. In addition, it was shown that the interest and participation of the construction workers can be increased by providing the 3D virtual scene for real construction work and various safety hazards occurring during equipment operation can be effectively removed in advance by the interactive worker education.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.31-42
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• 2013

This paper proposes a photogrammetric rectification method based on Bayesian approach as a method that eliminates vertical parallax between stereo images to minimize visual fatigue of 3D contents. The image rectification consists of two phases; geometry estimation and epipolar transformation. For geometry estimation, coplanarity-based relative orientation algorithm was used in this paper. To ensure robustness for mismatch and localization error occurred by automation of tie point extraction, Bayesian approach was applied by introducing several prior constraints. As epipolar transformation perspective transformation was used based on condition of collinearity to minimize distortion of result images and modification for input images. Other algorithms were compared to evaluate performance. For geometry estimation, traditional relative orientation algorithm, 8-points algorithm and stereo calibration algorithm were employed. For epipolar transformation, Hartley algorithm and Bouguet algorithm were employed. The evaluation results showed that the proposed algorithm produced results with high accuracy, robustness about error sources and minimum image modification.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1187-1200
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• 2002

This paper is concerned with the design or an LMI (Linear Matrix Inequality) -based H$\infty$ controller for a line of sight (LOS) stabilization system and with its robustness performance. The linearization of the system is necessary to analyze various nonlinear characteristics, but the linearization entails modeling uncertainties which reduce its performance. In addition, the stability of the LOS can be adversely affected by angular velocity disturbances while the vehicle is moving. As the vehicle accelerates, all the factors that are Ignored and simplified for the linearization tend to Inhibit the performance of the system. The robustness in the face of these uncertainties needs to be assured. This paper employs H$\infty$ control theory to address these problems and the LMI method to provide a suitable controller with minimal constraints for the system. Even though the system matrix does not have a full rank, the proposed method makes it possible to design a H$\infty$ controller and to deal with R and S matrices for reducing the system order. It can be also shown that the proposed robust controller has a better disturbance attenuation and tracking performance. The LMI method is also used to enhance the applicability of the proposed reduced-order H$\infty$ controller for the system given. The LMI-based H$\infty$ controller has superior disturbance attenuation and reference input tracking performance, compared with that of the conventional controller under real disturbances.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.06a
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• pp.137-159
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• 1999

Over the last three decades, Korean farming system has been directed to maximum agricultural production and to increase farmer's income through adoption of high-yielding crop varieties and high input of agrochemicals . These farming practices have resulted in problems of water-quality deterioration, soil degradation , and food safety. At present, over 40 million tones of animal waste are bing produced annually, which amounts to disposing the waste at the annual rate of 20 tones per ha in the total area of farming land in Korea. Nearly a half of total available water resources is used as irrigation water predominantly for rice paddy field. Thus, non-point source contamination of the water resources has been linked to agriculture across the nation. However, the extent to which agriculture contributes to the water quality is not fully known. Recently, Korean government provided various institutional measures to reduce the negative impacts of agricultural practices on the environ ental quality, and the Agricultural Environment Act was also passed by the legislature in 1998 and became effective January 1999. This Act does not cover the broad spectrum of the sustainable agriculture ; thus, the limited incentives within this Act are arguably ineffective to control the non-point source pollution. Recently new bulk blending of fertilizers(BB fertilizer) are bing produced (100, 000 tones in 1998) with Government subsidies. The BB fertilizers are to balance N-P-K ratio in the soils . Although the use of the BB fertilizers are encouraged with Government subsidies, non-point source pollution is still serious and will become worse. Precision farming is regarded as a new means for sustainable agriculture. It is a new technology that modifies the existing techniques and incorporates new one such as GIS, GPS , differential applicator to produce a new set of tools for the farmer to use. Precision farming, however, has constraints for individual farming practices. For exam le , farm size or parcel unit of each farmer is too small to adopt the precision agriculture on farmhouse-hold bases and farmer's ability to adopt the new technology is limited. However, it would be appropriate to establish local or regional cooperatives to operate such a precision farming system. It is recommended that Government provide sufficient incentives to help establish local and/or regional cooperatives.

• Environmental and Resource Economics Review
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• v.23 no.3
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• pp.453-472
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• 2014

Analyzing the effects of carbon emissions trading, which is scheduled to be introduced in Korea in 2015, requires an accurate assessment of $CO_2$ abatement costs by both industries and firms. Firms faced with regulatory constraints are unlikely to minimize their production costs due to rising production costs caused by allocative inefficiency of inputs. The use of a distance function would results in underestimation of $CO_2$ abatement costs, because it fails to capture the allocative distortion costs. Recognizing the disadvantage of the previous approach, first, this paper tests for allocative efficiency of input for the Korean steel industry over the period 1990-2010, then derives the marginal $CO_2$ abatement costs by applying a cost function approach. The hypothesis of allocative efficiency in inputs is rejected and the steel industry pays an annual average cost of 92,000 won in removing an additional ton of $CO_2$ over the sample period.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.293-307
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• 2003

Object-oriented development has been generalized, but object-oriented project planning and scheduling techniques have not been studied enough. Furthermore, it is difficult to apply the conventional software management techniques to object-oriented projects. Especially, the large scaled projects are increasing, but the project planing techniques for these large scaled projects have not been proposed enough. In this paper, we propose systematic techniques for OO based project scheduling. We suggest a 7 step-process for deriving the OO project schedule from the use-case diagram which is describing the functional requirements of the system. The proposed process includes identifying use-cases, drawing preliminary chart through interdependency analysis, identifying characteristics of each use case, determining the number of iteration, assigning use-cases to iteration, considering available resource and constraints, drawing revised PERT chart. Each step has the explanation of the input, output, and the guidelines needed to perform the step. The project scheduling technique proposed in this paper ran be used effectively in the planning phase which the purpose is to plan a development schedule to yield the high quality software in minimum time.

• Journal of Korea Multimedia Society
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• v.3 no.1
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• pp.23-33
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• 2000

In this paper, we describe an algorithm which can extract human faces with natural pose from complex backgrounds. This method basically adopts the concept that facial region has the nearly same gray level for all pixels within appropriately scaled blocks. Based on the idea, we develop a hierarchial process that first, a block image data with pyramid structure of input image is generated, and some candidate regions for facial regions in the block image are Quickly determined, then finally the detailed facial features; organs are decided. To find the features easily, we introduce a local gray level transform which emphasizes dark and small regions, and estimate the geometrical triangle constraints among the facial features. The merit of our method is that we can be freed from the parameter assignment problem since the algorithm utilize a simple brightness computation, consequently robust systems not being depended on specific parameter values can be easily constructed.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.97-105
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• 2015

This paper discusses the implementation of Bruun's FFT on a SIMD processor. FFT is an algorithm used in digital signal processing area and its effective processing is important in the enhancement of signal processing performance. Bruun's FFT algorithm is one of fast Fourier transform algorithms based on recursive factorization. Compared to popular Cooley-Tukey algorithm, it is advantageous in computations because most of its operations are based on real number multiplications instead of complex ones. However it shows more complicated data alignment patterns and requires a larger memory for storing coefficient data in its implementation on a SIMD processor. According to our experiment result, in the processing of the FFT with 1024 complex input data on a SIMD processor, The Bruun's algorithm shows approximately 1.2 times higher throughput but uses approximately 4 times more memory (20 Kbyte) than the Cooley-Tukey algorithm. Therefore, in the case with loose constraints on silicon area, the Bruun's algorithm is proper for the processing of FFT on a SIMD processor.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.30-40
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• 2010

The freeway congestion is largely generated by a mainline spillover of the exit ramp queue. So it is necessary to study for modeling of the phenomenon and applying the model. In this study, the authors evaluated applicability of the Supply-Demand model, which can express traffic flow for the freeway by applying flexibly supply and demand curves for capacity of the freeway. First the authors proposed methods processing input data required in the Supply-Demand model, such as sending & receiving functions and time-varying capacity constraints for the freeway mainline. After modeling the Supply-Demand application model, the authors applied the model to the site including congested Hongeun exit ramp in Seoul Ring-road, and improved the model by adjusting application techniques and calibrating parameters. The result of the analysis showed that the Supply-Demand model yielded a queuing pattern and queue location similar to them observed in the field data, and applicability of the Supply-Demand model was varified.