• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.251-254
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• 2003

A voltage stability assessment consists of the contingency screening, voltage stability analysis, and counter measures. A widely used index for the voltage stability assessment of power system is the reactive power margin. It shows some factors of voluntariness as following the status of power system and load levels for the target analyzing area. Therefore, it has a demerit that the absolute amounts of reactive power margin is not to be applied by the quantized margin criterion. This paper selects a vulnerable area by assigning the voltage instability for the particular contingency for the selection of vulnerable area in the respect of the investigation of reactive power margin or VQVI as an index of V-Q margin sensitivity in order to overcome the demerit. This will be able to grasp the V-Q margin sensitivity for the target analyzing area by presenting the ratio of power margin between the margin before and after contingency as following the calculation of reactive power margin. The presented method is applied to the voltage stability assessment for the Metropolitan area of 2003 KEPCO summer peak system.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.5
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• pp.17-24
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• 2012

The main purposes of the agricultural reservoir enlargement (ARE) project are to secure water supply reliability (WSR) for agriculture and to release environmental water during dry seasons. In this study, an operational rule that will simultaneously satisfy both the above issues was developed. Initial amount of water storage at the beginning of non-irrigation season (1st October) was divided into 3 stages, and the target level of water storage at the beginning of irrigation seasons (1st April) was set up. Required operational curves and release amounts were estimated based on the stages and target water levels. To evaluate the applicability of this rule, the amount of water released for environmental purposes and WSRs were analyzed for three reservoirs (Unam, Jangchi and Topjeong). The ratio between annual amount of release and additional amount of water storage were 1.6, 1.85, and 4.1 for the Unam, Jangchi, Tapjeong reservoirs, respectively. Also, the WSRs of all reservoirs were found to become higher than when the design standard was applied. Therefore, it is considered that the proposed rule is more suitable for the enlarged agricultural reservoirs operation as it satisfies the WSRs while securing the environmental water release.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.10
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• pp.791-798
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• 2018

The CFAR algorithm is mainly used for target detection in radar systems. In particular, OS CFAR is used in a non-uniform noise environment. However, it requires a large amount of computation, because it should sort reference cells in ascending order. This makes it difficult to apply the radar system in real time. In this paper, we describe how to reduce the computational burden of OS CFAR. We compared the power of the test cell and reference cell to determine only the presence or absence of target detection. The common reference cells overlapping in the reference cells of the three test cells are obtained. We first compare the test cell with the highest power value among the three test cells to the common reference cells. Next, we compare each test cell to general reference cells, excluding the common reference cells. The computation time is shortened by reducing the power comparison computation amounts.

• Journal of Fashion Business
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• v.8 no.6
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• pp.90-102
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• 2004

The purpose of this research is to identify the phases of the fashion merchandising process and the range of the fashion designer's work as well as performing degree at each stage according to the brand types of domestic women's apparel. The preliminary research was conducted with the chief designers of five woman's apparel manufactures located in Seoul and the questionnaires were collected from 192 fashion designers. They were measured by the five point Likert-type scales. For a data analysis, the Pearson's Correlation, ANOVA, Sheffe Test, MANOVA were used with SPSS V. 11.0. The results are as follows; 1. The steps which fashion designers of domestic apparel brand take in fashion merchandising process have been identified in 7 stages- Environment Information, Target Market Planning, Design Planning, Design Development, Price Settlement, Presentation & Line Release, Production. 2. The task achievement level of fashion designers in fashion merchandising process differs in brand types as well as in fashion merchandising stages. In NB, the designer's work was conducted in order of Design Planning(M=4.58)$\to$Presentation & Line release(M=4.31)$\to$ Environment Information(M=3.83)$\to$Target Market Planning(M=3.13). In DB, in order of Price Settlement (M=4.80)$\to$Production(M=4.33)$\to$Design Development(M=4.27)$\to$Design Planning(M=3.77)$\to$Presentation & Line release(M=3.20)$\to$Environment Information (M2.70). In GB, in order of Production(M=4.38)$\to$Design Planning(M=4.22)$\to$Price Settlement(M4.16)$\to$Environment Information(M=3.83)$\to$Merchandising Target Market (M=3.72)$\to$Design Development(M=3.65). 3. Considering the other factors such as sales, the amount of owning shops, item amounts that are related to the company size, this study shows that only the brand type affects designer's task achievement.

• Journal of Photoscience
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• v.9 no.2
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• pp.138-141
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• 2002

A photo-labile compound which is bioinactive but, upon irradiation with light, yields bioactive species is called as "caged compound". Photolysis of caged compounds generating bioactive species, has become a general method to produce a desired amounts of bioactive species in the specific time interval at the desired place or area of the target biological systems. For this purpose, we designed and synthesized caged hydroxyl radical., "Photo-Fenton Reagent" NP-IIl. NP-IIl has a strong absorption maximum at 377 nm and yields hydroxyl radicals upon UV light irradiation. The antioxidant activity of the ${\alpha}$ -lipoic acid and other naturally occurring compounds has been examined by using NP-IIl as a molecular probe. For example, upon photoirradiation of NP-lII with BSA or apolipoprotein of human low density (LDL), the significant oxidative modifications were observed in both cases. The oxidation was completely suppressed in the presence of ${\alpha}$-lipoic acid, which clearly demonstrates the strong hydroxyl radical scavenging activity of ${\alpha}$-lipoic acid. Other applications of NP-lII will also be described

• Korean Journal of Materials Research
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• v.14 no.1
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• pp.59-66
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• 2004

In the present study, ceramic brake pads without fiber phases were manufactured by the low temperature heat treatment below$ 700 ^{\circ}C$. The manufacturing parameters of ceramic brake pads and those levels were investigated by the analysis results of signal-to-noise ratios, ANOVA based upon the Taguchi method. The ceramic brake pads prepared in the Mg experiment had a friction coefficient of 0.30～0.55 very close to the target coefficient (0.35～0.45) of commercial brake pads utilized in the automobiles. The frictional properties of ceramic brake pads could be stabilized with the adjustment of amounts of lubricating additives. The optimum preparation conditions as well as batch formulations for the fabrication of non-fibrous ceramic brake pads were finally determined using Taguchi method in this study.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2961-2964
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• 2011

Greenhouse gas and energy reduction goal management system is announced to reduce national CO2 emission in 2011. The target business sector of the system has to follow the procedure of the system and get the assessment. The percentage of the national CO2 reduction goad is 30 % compared to the amounts of BAU. In railway business sector, 6 bodies are included in this system so that railway industry cannot stay and sustain its better position any more than other transportation industry. Most of the industry except Railway industry is struggling to develop its product more environmentally friendly and get the 3rd party certification like Eco-labelling and Carbon footprint. To get environmental certification, LCA method has to be applied because life cycle approach is needed to respond current environmental requirement. The purpose of this project is to facilitate railway vehicle manufacturer obtaining the environmental certification termed Korea EPD. By doing so, the environmental performance evaluation tool would be developed and modelled within the LCA framework and therefore applied especially for rail vehicle.

• Asia pacific journal of information systems
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• v.15 no.4
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• pp.153-164
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• 2005

Nowadays, large amounts of XML documents are available in the Internet. Thus, we need to analyze them multidimensionally in the same way as relational data. In this paper, we propose a new framework for multidimensional analysis of XML documents, which we call XML-OLAP. We base XML-OLAP on XML warehouses where all fact and dimension data are stored as XML documents. We build XML cubes from XML warehouses. We propose a new OLAP language for XML cubes, which we call XML-MDX. XML-MDX statements target XML cubes and use XQuery expressions to designate measure, axis and slicer. They incorporate text mining operations for aggregating text data. We apply XML-OLAP to the United States patent XML warehouse to demonstrate multidimensional analysis of XML documents.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.25-30
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• 2001

The purpose of this study is to present a basic data about the workability of high strength concrete to apply to a field of construction work. The main parameters are as follows; environmental temperature, elapsed time and the use of mineral admixture or not under the same mixing proportions. From the result, Adding amounts of superplasticizer to get a target slump were different in the respective temperature condition. Slump loss according to elapsed time was influenced by environmental temperature. the amount of superplasticizer and the slump loss were decreased by using mineral admixture(garnet powder) and by making concrete under lower temperature.

• 한국데이터정보과학회:학술대회논문집
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• 2005.04a
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• pp.164-173
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• 2005

Data mining is the method to find useful information for large amounts of data in database. It is used to find hidden knowledge by massive data, unexpectedly pattern, relation to new rule. The methods of data mining are decision tree, association rules, clustering, neural network and so on. The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud detection, data reduction and variable screening, category merging, etc. We analyze waste database united with local information using decision tree techniques for environmental information. We can use these decision tree outputs for environmental preservation and improvement.