• Smart Structures and Systems
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• v.17 no.2
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• pp.167-194
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• 2016

This paper investigates the Synergetics based Damage Detection Method (SDDM) for frame structures by using surface-bonded PZT (Lead Zirconate Titanate) patches. After analyzing the mechanism of pattern recognition from Synergetics, the operating framework with cooperation-competition-update process of SDDM was proposed. First, the dynamic identification equation of structural conditions was established and the adjoint vector (AV) set of original vector (OV) set was obtained by Generalized Inverse Matrix (GIM).Then, the order parameter equation and its evolution process were deduced through the strict mathematics ratiocination. Moreover, in order to complete online structural condition update feature, the iterative update algorithm was presented. Subsequently, the pathway in which SDDM was realized through the modified Synergetic Neural Network (SNN) was introduced and its assessment indices were confirmed. Finally, the experimental platform with a two-story frame structure was set up. The performances of the proposed methodology were tested for damage identifications by loosening various screw nuts group scenarios. The experiments were conducted in different damage degrees, the disturbance environment and the noisy environment, respectively. The results show the feasibility of SDDM using piezoceramic sensors and actuators, and demonstrate a strong ability of anti-disturbance and anti-noise in frame structure applications. This proposed approach can be extended to the similar structures for damage identification.

• Spatial Information Research
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• v.19 no.6
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• pp.1-10
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• 2011

The evaluation systems on the National Spatial Information Policy(NSIP) has been changed, since the Establishment and Use of the National Geographic Information System Act(NGIS Act, 2000) was abolished and the National Spatial Data Infrastructure Act(NSDI Act, 2009) was enacted. As compared to the NGIS Act, the policy evaluation systems for National Spatial Information are regarded as unified and centralized. However, some argue that the claim of budget and the legal feasibility of the NSIP was weakened. Given the different views on the two laws, this study aims at analyzing the changes in the evaluation system by comparing the NGIS Act and the NSDI Act. A Comparative Analysis framework is employed. The subjects of the comparative analysis are evaluation mechanism, evaluator, evaluation target and range, after-assessment utilization, and agent. In order to improve the effectiveness of the evaluation system, it is recommended that the clarification of evaluation purposes, institutional enhancement for evaluation agency, the development of evaluation indexes, the combination of top-down approach and bottom -up approach, and the increased linkage between budget and evaluation result.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.64-76
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• 2011

The current development trend and status of a personal air vehicle, known as the novel concept of a transportation that combines a personal car with a light general aviation aircraft, is summarized to investigate its feasibility as a future transportation. In the paper, the development programs of a personal air vehicle such as AGATE, PAVE, SATS and NGATS are first summarized, and then the design, technical development and testing activities of Terrafugia's Transition and Moller International's M400 Skycar, which will be commercialized in a short time, are reviewed. Based on the assessment of technical issues with those vehicles, the key technologies for the future development of the personal air vehicle are suggested with two basic requirements of safety and mobility.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.495-501
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• 2016

This study applied close-range digital photogrammetry to measure deformation of reinforced-soil wall as the passed time. We proposed to utilize the photogrammetric-board to determine 3D coordinates and compute exterior orientation parameters from the images without measuring control points. The displacements by the proposed method are compared with those of the Total-station. As results, measuring errors was within 5cm, and the deformation was not occurred in the 3 months. The proposed method using the photogrammetric-board therefore can be utilized to measure deformation of the reinforced-soil wall.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.261-269
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• 2002

The objectives of this paper are to study the use of geotextile tribes for dewatering high water content sludges and sediments and to evaluate their feasibility and affecting fsctors. To accomplish these objectives, pressure filtration tests were conducted on woven geotextile (Geotex$\circledR$ 46T and 1212T) fir high water content materials with a modified experimental apparatus. Test results indicate that 1) the filter cake formed on the inside of the geotextile tube is the major contributor to the retention of fine particles, but also causes a decrease in permeability, 2) controlling the formation of the filter cake and thus achieving a balance between soil retention and permeability is vital to a successful project, and 3) geotextiles, sludge properties, and filtration pressures have some effects on the dewatering efficiency and dewatering rate.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.192-204
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• 2012

For a severe accident of nuclear power plant, an approach to estimation of the radiological source term using a severe accident code(MELCOR) has been proposed. Although the MELCOR code has a capability to estimate the radiological source term, it has been hardly utilized for the radiological consequence analysis mainly due to a lack of understanding on the relevant function employed in MELCOR and severe accident phenomena. In order to estimate the severe accident source term to be linked with the radiological consequence analysis, this study proposes 4-step procedure: (1) selection of plant condition leading to a severe accident(i.e., accident sequence), (2) analysis of the relevant severe accident code, (3) investigation of the code analysis results and post-processing, and (4) generation of radiological source term information for the consequence analysis. The feasibility study of the present approach to an early containment failure sequence caused by a fast station blackout(SBO) of a reference plant (OPR-1000), showed that while the MELCOR code has an integrated capability for severe accident and source term analysis, it has a large degree of uncertainty in quantifying the radiological source term. Key insights obtained from the present study were: (1) key parameters employed in a typical code for the consequence analysis(i.e., MACCS) could be generated by MELCOR code; (2) the MELOCR code simulation for an assessment of the selected accident sequence has a large degree of uncertainty in determining the accident scenario and severe accident phenomena; and (3) the generation of source term information for the consequence analysis relies on an expert opinion in both areas of severe accident analysis and consequence analysis. Nevertheless, the MELCOR code had a great advantage in estimating the radiological source term such as reflection of the current state of art in the area of severe accident and radiological source term.

• Journal of Information Technology Services
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• v.11 no.4
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• pp.25-37
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• 2012

In recent year, the u-City construction projects which integrate IT technology into urban infrastructures are being pushed forward by many local governments. These projects contain various purposes in an aspect of regional economy : to reinforce a competitiveness of region by increasing efficiency of urban managements and to revitalize regional economy by stimulating the regional high-tech industries that related to u-City construction. In this context, regional economic impact assessment of u-City construction projects is particularly important because, it give us information about effectiveness of u-City construction policy as a stimulus of regional high-tech industries and the policy feasibility of u-City construction projects that can be a base of public projects. However, it is challenging to assess the impact of u-City projects on regional economy properly due to a lack of understanding about industrial classification, and specific industrial inputs related to u-City construction. In this study, we suggest u-City industrial classifications, and specific-industrial inputs induced by u-City construction projects based on associated legislations, business report for a u-City construction, and results from previous studies. Using these classification and industrial input, we also investigate the regional economic impacts of a u-City construction project in Wha-sung and Dong-tan cities employing Input-output analysis. The empirical results suggests that u-City industries have relatively high in production inducement, and value added inducement compared to input of other industrial sectors. These results indicate that regional economic impact of a Wha-sung and Dong-tan u-City construction project are relatively high, but economic impacts of u-City construction projects vary according to the regional industrial structure, and the specific expense accounts of u-City construction projects.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.3
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• pp.289-316
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• 2011

This study sets out to examine training courses for newly government-employed librarian for developing training contents to learn their basic knowledge, and suggests development model about training contents' planning, designing and making-process. In addition, in order to evaluate cyber training contents it devises self-evaluating tool, conducts a reviewing of questionnaire and measure by Delphi method. The final content made under the cyber contents development model proposes the six areas and 28th trials. Feasibility assessment for the purpose of evaluating educational contents, based on 17 questions to measure the factor analysis results, it yields, it yields 4 factors having more than .40 variance. Though differences in perception depending on factors did not show statistical significance, the difference in the adequacy of questions results significantly lower in some of them.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.24-31
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• 2020

A study on the H2O2 based low toxic hypergolic propellant was conducted. The fuel candidates were chosen as a mixture of Amine solvent and reactive additive. The analytical performance was calculated via the NASA CEA code and 96% Isp of the NTO/UDMH was confirmed. The ignition delay measurement with drop test was performed and all candidates showed less than 10 ms in the best performance cases. Based on these results, the feasibility of high response H2O2 based low toxic hypergolic propellant was confirmed.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.351-356
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• 2016

The carbon capture and storage (CCS), which collects and stores carbon dioxide in a geological site, is a promising option to mitigate climate change. However, there is the possibility of carbon dioxide leakage from the soil in the steps of collecting, transporting, and storing. To ensure the feasibility of this technology, it is important to monitor the leakage of carbon dioxide and to assess the potential impacts. As plants are sensitive to the changes in carbon dioxide in the soil environment, we can utilize plant parameter to detect the carbon dioxide leakage. Currently, chlorophyll a content is a conventional index indicating the changes in plants, however, this method is labor intensive and it only utilizes a small portion of leaves. To overcome its limitations, a simple spectroscopic parameter, DGCI (dark green color index), was suggested as an easy and quick indicator. In this study, we compared the values of chlorophyll a contents with DGCI from the experiment investigating the impacts of high underground $CO_2$ on grape plants. Results suggest that DGCI had high correlation with chlorophyll a contents and it has high potential to be utilized as an easy indicator to monitor plants' responses to $CO_2$ treatment.