• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2287-2293
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• 2009

Gas Chromatography-Mass Spectrometry (GC-MS) fingerprint analysis, Principle Components Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were introduced for quality assessment of Curcuma longa L. (C. longa). The GC-MS fingerprint method was developed and validated by analyzing 33 batches of samples of C. longa from different geographic locations. 18 chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression. Two principal components (PCs) were extracted by PCA. C. longa collected from Guizhou and Fujian were separated from other samples by PC1, capturing 71.83% of variance. While, PC2 contributed for their further separation, capturing 11.13% of variance. HCA confirmed the result of PCA analysis. Therefore, GC-MS fingerprint study with chemometric techniques provides a very flexible and reliable method for quality assessment of C. longa.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.6
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• pp.735-744
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• 2019

One of the key factors for recognition performance in the automatic target recognition for synthetic aperture radar imagery(SAR-ATR) system is reliability of the SAR target database. To achieve optimal performance, the database should be constructed using the images obtained under the same operating condition as the SAR sensor. However, it is impractical to have the extensive set of real-world SAR images, and thus those from the electro magnetic prediction tool with 3-D CAD models are suggested as an alternative where their reliability can be always questionable. In this paper, a method for similarity assessment between target SAR images is presented inspired by the fact that a target SAR image is mainly characterized by the features of scattering centers. The method is demonstrated using a variety of examples and quantitatively measures the similarity related to reliability. Its assessment performance is further compared with that of the existing metric, structural similarity(SSIM).

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.269-274
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• 2008

For fitness-for-service analyses of underground natural gas pipelines, engineering assessment methods against possible defects need to be developed. The assessment methods for high pressure pipeline of KOGAS, was developed using the full size pipe burst tests and the finite element analysis. It included the defect assessment methods for a single and multi-corrosion, corrosion in girth welding part, corrosion in seam welding part, the mechanical damage defects as dent and gouge, crack and large plastic deformation of API 5L X65 pipe. In addition, we developed method to assess pipeline integrity by internal and external load to buried pipeline. Evaluation results were compared with other methods currently being applied to the gas pipeline. The program of Windows environment is made for easily using assessment methods. It provides a consistent user interface, so non-professional technician can easily and friendly use the FFS program from company intranet. Several evaluation programs is easily installed using one installer. Each program constitutes a common input interface and the output configuration program, and evaluation result store and can be recalled at any time. The FFS program based on independent evaluation method is used to evaluate the integrity and safety of KOGAS pipeline, and greatly contribute to safe and efficient operation of pipeline. This paper presents experimental, analytical and numerical investigations to develop the FFS methods for KOGAS pipeline, used as high pressure natural gas transmission pipeline within KOREA. Also, it includes the description of the integrated program for FFS methods.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.235-244
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• 2011

Hydraulic hose assemblies deliver a fluid power in various oil pressure equipment such as construction machinery, automobile, aircraft, industrial machinery, machine tools and machinery for ships. Also, they are widely used as pipes in oil pressure circuit. When we estimate their lifetime, it is essential to conduct an accelerated life test by choosing the factor that suits the usage condition of the test object since traditional test method for estimating lifetime under the influence of various external factors incurs hardship in terms of time and expenses. The objective of this study is to propose an acceleration model that takes both temperature and pressure without flexing condition into consideration. The lifetime is estimated by applying the proposed temperature-nonthermal acceleration model to the test data. And we compare the proposed temperature-nonthermal acceleration model and the accelerated life equation suggested by John(1994).

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.310-312
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• 2002

The development of IEC 61400-21 provides firm basis for assessment of the impact of wind turbines on voltage quality. This paper presents analysis and modeling of the flicker emission of wind turbines. The paper concentrates on the theoretical aspects of the flicker algorithm, wind turbine characteristics and the generation of flicker during continuous operation of wind turbines. It also introduces a simplified assessment to limit the flicker emission.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.55-68
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• 2007

Recently, all kind of 21C-typed electronic goods show the tendency of hightechnology and digital convergence rapidly. Also, failure mechanism which differs from original goods concept presents. Today, failure mechanism which differs from one that was happened by restricted harmful environment material before adapted the raw of environment material is changing the paradigm of reliability engineering. Thus, when applied the environment matter of original and secondary material at the electronic goods were removed, reliability assessment method and prediction stay into low level. This study suggests as solution to overcome these phenomenon. The study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environment material of electronic goods and the study on reliability assessment method of PWB without environment material are progressed.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.161-170
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• 2007

As one of the major handling performances of the vehicle and tire, the steering feel is very important in the high speed where safety and refinement is a major concern for the drivers. This paper presents both subjective and objective techniques for the assessment of the steering feel including the on-center feel and steering response. For this, subjective evaluation method of the steering feel was studied at first and then objective parameters were selected by considering the process by which the steering feel is evaluated subjectively. From statistical analysis of subjective and objective data for the several vehicles and professional drivers, it was found that the subjective assessment of the steering feel could be successfully explained by means of the suggested objective parameters. Also, the main objective parameters related to the subjective assessment of the steering feel could be found.

• Journal of the Korean Geographical Society
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• v.40 no.1 s.106
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• pp.27-46
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• 2005

Land suitability assessment(LSA) is a useful method to assess land characteristics according to its physical, locational, and environmental characteristics, and then to classify it into several categories based on its usability and the necessity for conservation. Therefore, the credibility of this assessment result depends on the rationality of assessment method such as computation of suitability values and the criteria of ranking the land grade. This study focused on identifying problems in current LSA method by critically reviewing it, and aimed to suggest a suitable method for the assessment of land suitability. As a alternative method in this study, linear transformation method was used for scoring factors instead of critical values and the weight for each assessment factor. and all values of those factors were added to produce comprehensive suitability values. Those values were ordered and categorizied with suitability level based on the ratio of square measure. After comparing existing LSA method to the suggested alternative method, it is concluded that the alternative method was more suitable to assess the characteristics of lands than existing LSA method. This method was also suitable to represent the characteristics of various assessment factors. Field survey using satellite image clearly revealed the suitability of the alternative method compared to an existing method of land assessment. Furthermore, the alternative method of grading the land suitability improves the problem of using standardiZiation method and gives more flexibility, which makes this method very rational.

• Advances in Computational Design
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• v.2 no.2
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• pp.121-131
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• 2017

Collapse was one of the typical common geological hazards during the construction of tunnels. The risk assessment of collapse was an effective way to ensure the safety of tunnels. We established a prediction model of collapse based on Bayesian Network. 76 large or medium collapses in China were analyzed. The variable set and range of the model were determined according to the statistics. A collapse prediction software was developed and its veracity was also evaluated. At last the software was used to predict tunnel collapses. It effectively evaded the disaster. Establishing the platform can be subsequent perfect. The platform can also be applied to the risk assessment of other tunnel engineering.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.91-97
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• 2015

This paper specifies several considerations about assessing safety-critical software in the aerospace domain. In order to evaluate safety critical software in the aerospace industry, it is required to identify an information of evaluation criteria of software under evaluation. The information is specified in the standard, but determination of evaluation criteria cannot be decided by itself and depends on the results of safety assessment of a system and system design. Thus, this paper explains required information of system development standard and safety assessment standard to determine software evaluation criteria. It surveys existing methodologies about evaluating software, and suggests method which is adapted to evaluation of an advanced surface movement guidance and control system (A-SMGCS) software.