• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.116-123
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• 2001

An automated injection molding design methodology has been developed to optimize multiple quality attributes, which are usually in conflict with each other, in injection molded parts. For the optimization, commercial CAE simulation tools and optimization techniques are integrated into the methodology. To decal with the multiple objective problem the relative closeness computed in TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) is used as a performance measurement index for optimization multiple part defects. To attain robustness against process variation, Taguchi's quadratic loss function is introduced in the TOPSIS. Also, the modified complex method is used as an optimization tool to optimize objective function. The verification of the developed design methodology was carried out on simulation software with an actual model. Applied to production this methodology will be useful to companies in reducing their product development time and enhancing their product quality.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1355-1364
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• 2019

A recently published nuclear forensics methodology for source discrimination of separated weapons-grade plutonium utilizes intra-element isotope ratios and a maximum likelihood formulation to identify the most likely source reactor-type, fuel burnup and time since irradiation of unknown material. Sensitivity studies performed here on the effects of random measurement error and the uncertainty in intra-element isotope ratio values show that different intra-element isotope ratios have disproportionate contributions to the determination of the reactor parameters. The methodology is robust to individual errors in measured intra-element isotope ratio values and even more so for uniform systematic errors due to competing effects on the predictions from the selected intra-element isotope ratios suite. For a unique sample-model pair, simulation uncertainties of up to 28% are acceptable without impeding successful source-reactor discrimination. However, for a generic sample with multiple plausible sources within the reactor library, uncertainties of 7% or less may be required. The results confirm the critical role of accurate reactor core physics, fuel burnup simulations and experimental measurements in the proposed methodology where increased simulation uncertainty is found to significantly affect the capability to discriminate between the reactors in the library.

• Environmental Analysis Health and Toxicology
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• v.17 no.2
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• pp.95-107
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• 2002

This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOCs) in Korea. Target compounds included 1,3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the first part of the study, the performance of sampling and analytical methods was evaluated for the measurement of selected VOCs and carbonyl compounds in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis, while carbonyls by the DNPH-silica cartridge sampling with HPLC analysis. The methodology was investigated with a wide range of performance criteria such as repeatability, linearity. lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal standards. In addition, the sampling and analytical methods established in this study were applied to real field samples duplicately collected in various ambient environments. Precisions for the duplicate samples appeared to be comparable with the performance criteria recommended by USEPA TO-17. The overall precision of the sampling and analytical methods was estimated to be within 20 ∼ 30% for major aromatic VOCs such as BTEX, whereas the precision for major carbonyl compounds such as formaldehyde and acetaldehyde was within 10 ∼ 20% for field samples. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.141-142
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• 2012

Estimating the productivity of labor has relied on the experience and intuition of an estimator, or productivity data, such as standard in practical estimation. However, when new technologies and new construction methods employed in the construction industry, Dependence of a quantity surveyor's intuition is increased. This is because of the lack of a systematic methodology which models, estimates, and measures the labor productivity, Due to the historical productivity data is unavailable. Even thought project history data contains information that is important to predict the performance of a project, It can not provide valuable information to model, estimate, and measure the labor productivity. This is because 1) the absence of the productivity measurement system with consistency, 2) the difficulty of reusability of historical data collected. Therefor, this study suggests a methodology which build a productivity model by measuring the productivity of labor and collecting the historical data systematically. In addition, this methology is applied to develop a productivity model of shop-drawing and manufacturing process using descrete event simulation.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.17-25
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• 2009

This paper presents a methodology for a fall detection using the feature extraction method based on the neural network with weighted fuzzy membership functions (NEWFM). The distributed non-overlap area measurement method selects the minimized number of input features by removing the worst input features one by one. Nineteen number of wavelet transformed coefficients captured by a triaxial accelerometer are selected as minimized features using the non-overlap area distribution measurement method. The proposed methodology shows that sensitivity, specificity, and accuracy are 95%, 97.25%, and 96.125%, respectively.

• Journal of Information Technology Services
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• v.9 no.1
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• pp.141-156
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• 2010

Service industry has become the integral part of economy. And the activation of industry requires a scientific and systematic approach. As one of these kinds of efforts, IBM presented a service model which consisted of strategies, processes, technology, manpower and so on through Service Science. And IBM raised the needs of considering the main issue and methodology of service model's scientific approach. On that account, this study worked out factorial definitions and measurable items by the four components of service model presented by Service Science in order for it to be measured through studies on related literature and interviews of specialists. In order to prepare an opportunity of categorizing the conception of the service model of which character was strongly intangible and of systematically approaching to it, the investigator examined related literature and applied it QFD methodology. Through this kind of redefinition, the investigator concretely conceptualized the service model which was standstill at the level of theoretical approach so far and presented guidelines with which researchers could classify it more concretely. In addition, the investigator tried to present a systematic frame which could be applied to business by working-level officials or decision-makers. Therefore, the investigator expects that study findings will be used as references for the design or implementation of service-oriented business model.

• Korean Journal of Human Ecology
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• v.21 no.6
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• pp.1059-1082
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• 2012

The purpose of this study was to analyze the trends, research methodology and findings of various researches on family resilience published in Korea over the past 13 years. A total of 93 publications related to family resilience between 1999 and June of 2012 were analyzed; 72 journal articles and 21 doctoral dissertations which had not been published in academic journals. The results are as follows; (1) There has been steady increase in the number of related researches since 1999, with a significant increase since the mid-2000s as various nontraditional families emerged and the perception of family problems began to change. (2) With regards to the methodology, the majority of the studies were empirical, using quantitative methods in both data collection and analysis. Most measurement scales employed were based on inventories developed by foreign researchers. (3) The research subjects encompass a wide range of individuals and groups from both vulnerable families and families from the general population. Additionally, some researches focused on special interest areas including program development & evaluation and scale development. Although research on family resilience has increased in quantity, there needs to be more qualitative, longitudinal and theory grounded studies on different families and individual types to better understand family resilience in depth. In addition, specific measurement scales reflecting the unique Korean family culture should be developed. Other challenges and suggestions for future research on family resilience are discussed.

• IE interfaces
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• v.24 no.1
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• pp.24-39
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• 2011

In this paper, we study the methodology for the measurement and integration of market risk and credit risk using Copula. We apply the methodology of Rosenberg, and Schuermann(2006) to the assets of pension system. Firstly we estimate dynamics of risk factors and their effects on investment returns, then use the estimated result to simulate future movement of risk factors and distribution of investment returns. Finally we measure integrated risk using integrated return distribution by Copula and simulated future investment return distributions. We found the integrated risk changing with the correlation of risks and investment weights of risks and confirmed the diversification effect of risks. This result is consistent when we use normal Copula and normal marginals, t-Copula and t(3) marginals, and normal Copula and non-parametric marginals. And in the case of non-parametric maginals, larger integrated risk is calculated. It means that use of non-parametric marginals is more conservative.

• Journal of Radiation Industry
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• v.9 no.1
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• pp.21-27
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• 2015

The domestic Radiation Technology is integrated into and utilized in various areas and is closely related to the industrial growth in Korea. The domestic use of radiation and RI (Radioisotope) increases in quantity every year, however the level of technology is poor when compared to other developed countries. Manpower training is essential for the development of Radiation Technology. Therefore, this study aimed to propose a methodology for designing systemic education and training model in the field of measurement and analysis of radiation. A survey was conducted to design education and training model and the training program for measurement and analysis of radiation was developed based on the survey results. The education and training program designed in this study will be utilized as a model for evaluating the professional development and effective recruitment of the professional workforce, and can be further applied to other radiation-related fields.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.150-156
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• 1994

To meet the process requirement of semiconductor device manufacturing, it is necessary to improve the alignment accuracy in exposure equipments. We developed the excimer laser stepper and will describe the methodology for alignment measurement and experimental results. Our wafer alignment system consists of off-axis optics, TTL(Through The Lens) optics and high precision stage. Off-axis alignment utilizes the image processing and /or diffraction from thealign marks of off-centered chip area. On the other hand, TTL alignment can be used for the die-by-die alignment using dual beam interferometry. When only off-axis alignment was used, the experimental alignment error(lml+3 .sigma. ) was 0.26-0.29 .mu. m, and will be reduced down to 0.15 .mu. m by adding TTL alignment.