• Korean Journal of Human Ecology
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• v.19 no.1
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• pp.127-136
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• 2010

This research subdivided the groups of baby clothes purchasers by consumer value factors in order to study clothing behavior by the value group of baby clothes purchasers and to examine differences in shopping propensity, pursuit benefits, evaluation criteria, and utilization of information sources depending on the value groups 1. A total of three factors - the pursuit of a stable life, the pursuit of achievement, and the pursuit of pleasure - were derived by conducting a factor analysis on the value dimensions of baby clothes purchasers. The value types of baby clothes purchasers were classified into three groups - the group of the pursuit of achievement, the group of the pursuit of stability and pleasure, and the passive group as the result of conducting cluster analysis on the basis of three types of personal value factors. 2. In the difference of shopping propensity by the value group, the group of the pursuit of achievement and the group of the pursuit of stability and pleasure were found to be the group having economical shopping propensity. In the difference of pursuit benefits by the value group, the passive group appeared to be the group in pursuit of fashion, and it could be seen that the group of the pursuit of achievement and the group of the pursuit of stability and pleasure were highly interested in the pursuit of individuality and practicality. 3. In the evaluation criteria of clothes by the value group of baby clothes purchasers, the group of the pursuit of achievement was found to consider physical criteria as important evaluation criteria, and the group of the pursuit of stability and pleasure was found to consider aesthetic criteria as important evaluation criteria. In the utilization of information sources by the value group of baby clothes purchasers, the passive group was found to be influenced most by market-oriented information sources.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.15-23
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• 2021

Most of the open-source decision tree algorithms are based on three splitting criteria (Entropy, Gini Index, and Gain Ratio). Therefore, the advantages and disadvantages of these three popular algorithms need to be studied more thoroughly. Comparisons of the three algorithms were mainly performed with respect to the predictive performance. In this work, we conducted a comparative experiment on the splitting criteria of three decision trees, focusing on their interpretability. Depth, homogeneity, coverage, lift, and stability were used as indicators for measuring interpretability. To measure the stability of decision trees, we present a measure of the stability of the root node and the stability of the dominating rules based on a measure of the similarity of trees. Based on 10 data collected from UCI and Kaggle, we compare the interpretability of DT (Decision Tree) algorithms based on three splitting criteria. The results show that the GR (Gain Ratio) branch-based DT algorithm performs well in terms of lift and homogeneity, while the GINI (Gini Index) and ENT (Entropy) branch-based DT algorithms performs well in terms of coverage. With respect to stability, considering both the similarity of the dominating rule or the similarity of the root node, the DT algorithm according to the ENT splitting criterion shows the best results.

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.239-243
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• 2001

One of the most important justifications of conservation of ecosystem and biodiversity is that diversity begets stability. Impact of biodiversity on community and ecosystem function has long been debated in science. Here we report the stability analysis of soil oribatid mite communities from environmentally stressed habitat(Namsan) and relatively well preserved habitat (Kwangreung) with the perspective of consistency as a primary criteria of stability. Stability of oribatid mite communities were evaluated with turnover rate, constancy analysis, b diversity index, and absolute abundance, abundance ranking, and the presence or absence of species over time. Out of 6 criteria, three consented that oribatid community from Kwangreung was more stable than that from Namsan. Those are turnover rate in litter layer, constancy analysis, and absolute abundance. Feasibility of stability analysis using oribatid mites was further discussed, rendering further study.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.943-946
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• 1993

This paper presents design criteria of an overlapping decentralized controller by investigating the controllability and closed loop stability of the expanded system. To determine the criteria we classify the overlapping decentralized controller into an overlapping expanded controller and a contractible controller. It is shown that conditions of system expansion to design these controllers are differently used. The overlapping expanded controller needs the aggregation conditions due to the importance of a structure of the expanded system. The contractible controller which intends to use in the original space needs the restriction because of stability of the original system.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.17-27
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• 2022

A certain level of stability margin airworthiness criteria should be met to secure robustness against uncertainties between the real plant and the model in a flight control system design. The U.S. Department of Defense (DoD) specification of MIL-F-9490D and airworthiness certification standard of MIL-HDBK-516B uses gain and phase margin criteria of flight control system. However, the same stability margin criteria is applied at all development phases without considering the design maturity of each development phase of the aircraft. Ultimately, a problem arises when the aircraft operation envelope is excessively restricted. This paper proposes the relation of handling qualities and stability margin, and presents re-established stability margin criteria as a development phases and verification methods. The results of the research study are considered to contribute to the verification of the stability margin criteria more flexibly and effectively by applying the method to not only the currently manned developing aircrafts but also the unmanned vehicle to be developed in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.325-331
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• 2023

The navigational officer's knowledge about securing stability, an essential factor for promoting the safe operation of ships, should be improved along with advancement in ship technology, such as the large-sized ships and the appearance of autonomous ships. Accordingly, this study conducted a survey on stability, targeting navigational officers, and analyzed empirical awareness using general characteristics. Navigational officers had a high level of understanding of the stability criteria for a higher rank, but lacked the understanding of the special criteria for specific ship types. Of the total respondents, 87.6% were using a loading computer to evaluate stability. The GM scored the highest (3.891/5.000 points) as a method of evaluating stability on the ship. Further, whether the stability was secured was determined based on the GM and stability criteria. Most navigational officers replenish additional ballast water to improve the stability and use a small angle of rudder in the case of lacking stability. The results of this study are intended to be used as important data for improving education and research on operator-centered stability in the future by evaluating the empirical awareness of navigational officers on the ship stability.

• Journal of Pharmacopuncture
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• v.12 no.4
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• pp.33-50
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• 2009

Objectives : This study was conducted to confirm validation and stability of concentration analysis method of pure melittin (Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods : All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Standard solutions of melittin (SIGMA, USA) and test substances were dispensed and were analyzed with HPLC for Sweet BV to secure the validation of analysis. Results : 1. Measurement of system suitability of Sweet BV satisfied criterion of below 3%. 2. Confirming Linearity of Sweet BV in 10-200${\mu}g/m\ell$ solution yielded correlation coefficient (r) of 0.995 and accuracy of 85-115% which satisfy criterion. 3. Measurement of Specificity of Sweet BV didn't yield any substance affecting the peak of test substances, but detected at 21.22min verified as the test substance. 4. Confirming Intra-day of Sweet BV, accuracy and precision of 0.1, 100${\mu}g/m\ell$ were 105.70, 95.81 and 0.66, 0.73, respectively, satisfying both criteria of accuracy (85-115%) and precision (within 10%). 5. To measure Stability in autosampler, all samples used in Intra-day reproducibility sat in the autosampler for five hours and were re-analyzed. Both variability and precision satisfied the criteria. 6. Homogeneity of Sweet BV (0.1, 100${\mu}g/m\ell$) at upper, middle, and lower layers all satisfied the accuracy and precision criteria. 7. Stability of Sweet BV (0.1, 100${\mu}g/m\ell$) at room temperature for four hours and refrigerated for 7 days all satisfied the criterion. 8. For the measurement of Quality control, QC samples measured on the first and eighth day all satisfied accuracy and precision criteria. Conclusion : Above experiment data satisfies validation and stability of concentration analysis method of Sweet BV.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.934-939
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• 2004

The Korea high-speed rail, based on the French design. It also implements new concept to increase the strength of bridge deck by adding an impact factor (dynamic intensity factor) in static load. In order to assure the dynamic stability, SYSTRA and Jeseph Penzien, a professor in CEC (the US) conducted a dynamic stability review on design phase. Analyzing the review results, they developed design criteria for dynamic behavior. This study deal with operating PSC box GIRDER equipped with measurement equipment or measured data of Seoul $\∼$ Taejeon, P.S.C BOX GIRDER bridge and steel comsition bridge equipped with measurement equipment based on structual knowledge about configuration of measuring sensor, response analysis of structure when train runs was performed by using measured data of PSC box girder to directly compare with design criteria. moreover, the dynamic stability with comparison of high-speed rail construction criteria was reviewed and analyzed based on historical records.

• Journal of the Korean GEO-environmental Society
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• v.8 no.3
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• pp.51-57
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• 2007

In the design of slopes during rainfall, the groundwater level is assumed to be located at the ground surface, based on the change in characteristics of rainfall. In addition, stability investigations are performed for large cut slopes in the design of slopes while standard inclinations specified in the design criteria are applied for the slopes that stability investigations are not performed. In spite of the strengthened criteria of groundwater location, slope failures continuously occur during heavy rainfall, regardless of magnitude of slopes. In order to investigate the cause of the failures, stability investigations have been performed on standard inclination of slopes suggested in the design criteria for both dry and rainfall cases by ground condition in this research. Despite that standard inclination of slopes specified in the design criteria should be stable for both dry and rainfall cases, the results show that standard factor of safety has not been obtained in many cases; more than 50% of total cases for dry cases and more than 65% of total cases for rainfall case. Based on the results, this paper indicates the problems in the current design criteria and proposes the plans for establishment of countermeasure.

• Geomechanics and Engineering
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• v.24 no.3
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• pp.281-293
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• 2021

Uncertainties in geomechanical input parameters which mainly related to inappropriate data acquisition and estimation due to lack of sufficient calibration information, have led wellbore instability not yet to be fully understood or addressed. This paper demonstrates a workflow of employing Quantitative Risk Assessment technique, considering these uncertainties in terms of rock properties, pore pressure and in-situ stresses to makes it possible to survey not just the likelihood of accomplishing a desired level of wellbore stability at a specific mud pressure, but also the influence of the uncertainty in each input parameter on the wellbore stability. This probabilistic methodology in conjunction with Monte Carlo numerical modeling techniques was applied to a case study of a well. The response surfaces analysis provides a measure of the effects of uncertainties in each input parameter on the predicted mud pressure from three widely used failure criteria, thereby provides a key measurement for data acquisition in the future wells to reduce the uncertainty. The results pointed out that the mud pressure is tremendously sensitive to UCS and SHmax which emphasize the significance of reliable determinations of these two parameters for safe drilling. On the other hand, the predicted safe mud window from Mogi-Coulomb is the widest while the Hoek-Brown is the narrowest and comparing the anticipated collapse failures from the failure criteria and breakouts observations from caliper data, indicates that Hoek-Brown overestimate the minimum mud weight to avoid breakouts while Mogi-Coulomb criterion give better forecast according to real observations.