• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.2
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• pp.231-236
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• 2012

This work presents the application of the DFSS (Design for Six Sigma) methodology to optimizing both the linearity and the sensitivity of the output voltage of a Hall-effect rotary position sensor. To this end, the dimensions and relative positions of a permanent magnet with reference to a Hall sensor are selected as the design factors for a full factorial design. In order to evaluate the output voltage of the rotary position sensor at each run in the experimental design, analytical solutions to the magnetic flux density were obtained using the Biot-Savart law and the relations between the magnetic flux density and the output voltage intrinsic to a Hall sensor. Through measurements of the improved output voltage of the rotary position sensors manufactured using the optimized design factors, the proposed method is shown to be simple and practical.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.412-417
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• 2013

Analytical modeling of photovoltaic power systems has been receiving significant attentions in recent years in that it is easy to apply for prediction of its dynamics and fault detection and diagnosis in advanced engineering technologies. This paper presents a novel probabilistic modeling approach for such power systems with a big data sequence. Firstly, we express input/output function of photovoltaic power systems in which solar irradiation and ambient temperature are regarded as input variable and electric power is output variable respectively. Based on this functional relationship, conditional probability for these three random variables(such as irradiation, temperature, and electric power) is mathematically defined and its estimation is accomplished from ratio of numbers of all sample data to numbers of cases related to two input variables, which is efficient in particular for a big data sequence of photovoltaic powers systems. Lastly, we predict the output values from a probabilistic model of photovoltaic power systems by using the expectation theory. Two case studies are carried out for testing reliability of the proposed modeling methodology in this paper.

• The Research Journal of the Costume Culture
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• v.14 no.4
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• pp.657-669
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• 2006

This study is to investigate the previous cases of plural eclecticism through the works of Vivienne Westwood, who contributed to the spread of innovative and eclectic English fashion out to the world as well as to review plurality and its phenomena since the 20th century more systematically. In terms of research methodology, the phenomena of plural eclecticism were examined from social and cultural perspectives, whereas bibliographic research and case study were performed for the phenomena of eclecticism in fashion. From the perspective of plural eclecticism, the results from analyzing the works of Vivienne Westwood by the divisions of temporal eclecticism, spatial eclecticism, and contingent eclecticism are described in the following. First, Vivienne Westwood emphasized historicism tendency of temporal eclecticism. Her efforts to try to modernize history went beyond ages and social classes including men's clothing, prostitutes' costumes, craft items, and dresses for royal family. Second, her spatial eclecticism was reflected on the first collection themes inspired by the American Indians or borrowed from the names of Voodoo in the Tropics. Finally, infra-fashion as an expression of contingent eclecticism of Vivienne Westwood's works can be interpreted as plural eclecticism which shows contingent eclecticism and historic eclecticism at the same time. This study aimed at proving preceding implications concerning recent plural eclecticism through the analysis of the works of Vivienne Westwood who tried a radical design of plural eclecticism in an effort to modernize the tradition of England in the circumstances where a number of trends and styles exist together, with their own uniqueness and values.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1528-1534
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• 2001

In order to improve Leak-Be(ore-Break methodology, more precisely the crack growth evaluation, a round robin analysis was proposed by the CEA Saclay. The aim of this analysis was to evaluate the crack initiation life, penetration life and shape of through wall crack under cyclic bending loads. The proposed round robin analysis is composed of three main topic; fatigue crack initiation, crack propagation and crack penetration. This paper deals with the first topic, crack initiation in a notched pipe under four point bending. Both elastic-plastic finite element analysis and Neuber's rule were used to estimate the crack initiation life and the finite element models were verified by mesh-refinement, stress distribution and global deflection. In elastic-plastic finite element analysis, crack initiation life was determined by strain amplitude at the notch tip and strain-life curve of the material. In the analytical method, Neuber's rule with the consideration of load history and mean stress effect, was used for the life estimation. The effect of notch tip radius, strain range, cyclic hardening rule were examined in this study. When these results were compared with the experimental ones, the global deformation was a good agreement but the crack initiation cycle was higher than the experimental result.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.549-572
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• 2004

This paper develops the methodology for the indexation of Sustainable Development Indicators(SDIs) in 4 sectors(social, environmental, economic, and institutional sectors), and provides the empirical results of Sustainable Development Index(SDI) for Korea from 1990 to 2001. Given 1995 as the basic year, the trend of SDI for Korea displays a slowly curving U-shape. The down trend of SDI until mid-90's results from the decline of SDI in economic and environmental sectors, and the uptrend of SDI after mid-90's results from the sharp rising of SDI in social and institutional sectors. The implication of the results is that Korea generally shows a positive trend toward the sustainable development. However, there should be a careful consideration about partly downward trend in individual SDIs, because of the different trend of SDI in each sector.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.417-429
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• 2015

Evaluation of traffic data quality is a backbone of better traffic information and management systems because it directly affects the reliability of traffic information. This study developed an integrated index for evaluating the quality of archived intelligent transportation systems (ITS) data. Two novel indices including spatio-temporal consistency and severity of missing data were devised and integrated with existing indices such as availability and completeness. An evaluation framework was proposed based on the developed integrated index. Both analytical hierarchical analysis (AHP) technique and entropy method were adopted to derive mixed weighting values to be used for the integrated index. It is expected that the proposed methodology would be effectively used in enhancing the quality of traffic data as a part of traffic information system.

• Journal of Oriental Neuropsychiatry
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• v.24 no.4
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• pp.373-384
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• 2013

Objectives: The purpose of this study is to understand the cognition of the initiation of diseases of North Korean refugees in South Korea. Methods: 9 North Korean refugees hospitalized in Oriental Neuropsychiatry of National Medical Center participated in the interview. The statements were analyzed by using the phenomenological research methodology and Giorgi's analytical method, in particular, was applied. Results: A total of 4 categories and 15 sub categories were derived from the participants' descriptions. North Korean refugees who thought their diseases have begun while living in North Korea coming to South Korea, have fire disease because of the strict social system, limitations imposed on their actions, and the violence of their husbands. And who thought during escaping from North Korea, have anxiety about being killed, found and transferred to North Korea. They also suffered from a sense of guilt towards their family who were left behind as well as from depression. Consequently, they thought their skeletal diseases have begun during this period. Who thought during their period in Korea, their diseases like fire disease and depression have been worsen because of unfamiliar circumstances and doctors who said their problems had been caused by psychiatric disorder. Nevertheless, they did their jobs, felt happy and had a will to be cured thingking possibilities of overcoming diseases. Conclusions: These results suggest that various factors during different periods in the life of North Korean refugees could have an effect on their present diseases.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.1-9
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• 2012

Emerging three-dimensional television (3DTV) as a new IT product shows a possibility that television is not for just watching broadcasting, but an attractive tool for applying it to our real life. Three dimensional television is generally more effective and attractive than two-dimensional television (2DTV). But it still needs continuous technological improvement to solve its inherent limitations until many customers decide to purchase 3DTVs without hesitation. Innovative products like 3DTV encounter a quality problem leading purchase decision by customers. Quality is regarded as one of the most important factors affecting customers to adopt and use the product. Furthermore, measuring quality effectively is considerable for the 3DTV research. In this paper, we suggest the Analytic Hierarchy Process(AHP) method for evaluating 3DTVs in a view of quality. We describe quality criteria affecting the 3DTV selection through a literature survey and develope an analytical method for measuring quality. We classify the quality of 3DTV into four types and suggest a concept of the quality ratio as a measurement criteria instead of the quality gap. Though a numerical example, we show how priorities of 3DTV with versatile manufacturers is computed.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.71-80
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• 1997

This paper suggests a Map Accuracy Standards by analyzing U.S. National Map Accuracy Standards, by considering korean terrain feature and statistical error theory for paper and digital maps on the scale of 1:50,000. Map accuracy standards require horizontal accuracy to be reported as a circular error with 90% confidence level through Linear Error Probable(LEP) theory and Circular Error Probable(CEP) theory. In order to verify the proposed methodology for positioning accuracy testing, several kinds of test point were selected and tested. These test points were extracted at the centers of roads and bridges, the comers of the independent building, the edges of geographical botany, and the tops of mountains. The positioning accuracy assessment was peformed by comparing the positions of test points in digital maps generated three different sources with those acquired by high accurate GPS surveying. The digital maps were produced from aerial photographs and SPOT satellite image using analytical plotter and 1:50,000 paper map.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.539-549
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• 2017

This paper proposes an analytical methodology of station capacity calculation on high - speed railway. Our method explicitly takes into account the effect of the number of sidings and the combination of train halting patterns (stop - stop, pass - stop, stop - pass, pass - pass) on the capacity of a station. To verify the reliability of our model, we conducted capacity analysis of selected stations using the Railsys simulator. We found that the difference in calculated capacity between our model and Railsys was less than 10%. After Monte Carlo simulation, our model was determined to be a good one. In addition, the consistency in capacity between our model and the train-path allocation program (Korea Rail Network Authority) was statistically significant.