• Asia pacific journal of information systems
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• v.16 no.2
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• pp.1-25
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• 2006

Application of appropriate research methods has assumed an important role in knowledge accumulation endeavors in the scientific research community. The current study reported here summarizes how we used the empirical methods in IS research, what we need to improve in using empirical study as research methodology through the set of comprehensive research guideline. From the survey and review of seminal and classical research guidelines, we developed our own 28 checklist for research design, statistical analysis, and conclusion, which can be commonly applied to all articles that employ inferential statistical methods in IS research. Then, we critically evaluated the usage of empirical research methods in major IS journals by using the checklist, with the goal of improving the quality of academic papers. In this study, we scrutinized four major IS journals which published empirical papers from 1991 to 2000: MIS Quarterly, Journal of MIS, Information Systems Research, and Decision Sciences. As a result of intensive evaluation work, we could highlight many areas that are lagging and call for greater attention with regard to the proper usage of empirical study in IS research. The research findings in this study can be referred as checklist and guideline when IS researcher applies the empirical method.

• Journal of Korean Society for Quality Management
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• v.37 no.4
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• pp.31-42
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• 2009

Various studies have been undertaken in order to effectively understand customer requirements. Kano proposed a dualistic approach, physical fulfillment and customer satisfaction, to differentiate Attractive, Must-be, One-dimensional quality attributes. As there were a few limitations on the Kano's method, researchers have proposed improved methods. However, there have been few empirical evidences that the improved methods are superior to the original Kano's method for identifying relevant quality attributes. The objective of this study is to provide a comparative study on Kano and improved Kanomethods based on empirical analysis of quality attributes on University services. For the analysis of the questionnaire formats, the Kano's original 5 scale questionnaire is more effective than improved methods, direct and 3 scale questionnaire. For the analysis of evaluation methods, the original Kano and Timko's method using the evaluation table are more effective than quantifying methods, Domouchel and Lim's methods.

• International Journal of Highway Engineering
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• v.16 no.1
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• pp.57-62
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• 2014

PURPOSES : Capacity is a main factor of determining the number of lane in highway design or the level of service in road on operation. Previous studies showed that breakdown may occur before capacity is reached, and then it was concluded that capacity is a stochastic value rather than a deterministic one. In general, estimating capacity is based on average over maximum traffic volume observed for capacity state. This method includes the empirical distribution method(EDM) and would underestimate capacity. This study estimated existing empirical methods of estimating stochastic highway capacity. Among the studied methods are the product limit method(PLM) and the selected method(SM). METHODS : Speed and volume data were collected at three freeway bottleneck sites in Cheonan-Nonsan and West Sea Freeway. The data were grouped into a free-flow state or capacity state with speeds observed in the bottlenecks and the upstream. The data were applied to the empirical methods. RESULTS : The results show that the PLM and SM estimated capacity higher than EDM. The reason is that while the EDM is based on capacity observations only, the PLM and SM are based on free-flow high volumes and capacity observations. CONCLUSIONS : The PLM and SM using both free-flow and capacity observations would be improved to enhance the reliability of the capacity estimation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.665-670
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• 2006

In this paper, the results of empirical methods and the numerical analysis were compared and investigated on the lateral displacement due to embankment in soft soil. The empirical methods gave different results so the possibility of lateral displacement could not be determined only by the empirical methods. The numerical analysis could be used so effectively that its result showed useful lateral and vertical displacements with depth and distance.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.215-222
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• 2001

Uncertainty study of shear strength characteristics of the marine clays was carried out based ell In-situ tests and laboratory tests on tile south-east coastal region of the Korean peninsula. Theoretical analyses were studied using both tile spherical cavity expansion theory in finite soil mass and the strain path method to determine tile cone factor using the undrained shear strengths obtained by in-situ tests, and the empirical methods in accordance with the ultimate resistance theory were also discussed. Analysis show that the empirical methods suggest more reasonable value than that of theoretical methods in terms of comparing the cone factor estimated using linear regression and frequency distribution analyses. The cone factors obtained by the empirical methods are 18, 15, and 6 respectively, from the results of total cone resistance, effective cone resistance, and excess porewater cone resistance method, and the estimated were similar to those of previous researcher's.

• Geomechanics and Engineering
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• v.30 no.1
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• pp.11-26
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• 2022

One of the most important issues in tunneling, is the squeezing phenomenon. Squeezing can occur during excavation or after the construction of tunnels, which in both cases could lead to significant damages. Therefore, it is important to predict the squeezing and consider it in the early design stage of tunnel construction. Different empirical, semi-empirical and theoretical-analytical methods have been presented to determine the squeezing. Therefore, it is necessary to examine the ability of each of these methods and identify the best method among them. In this study, squeezing in a part of the Alborz service tunnel in Iran was estimated through a number of empirical, semi- empirical and theoretical-analytical methods. Among these methods, the most robust model was used to obtain a database including 300 data for training and 33 data for testing in order to develop a machine learning (ML) method. To this end, three ML models of Gaussian process regression (GPR), artificial neural network (ANN) and support vector regression (SVR) were trained and tested to propose a robust model to predict the squeezing phenomenon. A comparative analysis between the conventional and the ML methods utilized in this study showed that, the GPR model is the most robust model in the prediction of squeezing phenomenon. The sensitivity analysis of the input parameters using the mutual information test (MIT) method showed that, the most sensitive parameter on the squeezing phenomenon is the tangential strain (ε_θ^α) parameter with a sensitivity score of 2.18. Finally, the GPR model was recommended to predict the squeezing phenomenon in tunneling projects. This work's significance is that it can provide a good estimation of the squeezing phenomenon in tunneling projects, based on which geotechnical engineers can take the necessary actions to deal with it in the pre-construction designs.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.949-959
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• 2006

Despite of the popularity of using empirical methods for support design, empirical rules suffer from the inherent problem of providing no indication of the safety degree of the design. For the support design of large span tunnel, it was considered that the empirical design guidelines should be augmented by more explicit design methods. This paper presents an overview of the analytical support design methodology that is used to refine initial empirical recommendations. The initial support design supplemented by analytical methods is validated by probabilistic and deterministic approach applied to stress-induced and structurally controlled gravity-driven instability problem each. As a result, the extent of the potential failure zone is sorted out and numerical parametric studies were performed to gain insight into the overall behavior of tunnel in the potential failure zone. Concequently, it was decided that additional conservation techniques have to be planed as a reserved support pattern.

• Communications for Statistical Applications and Methods
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• v.18 no.2
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• pp.245-255
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• 2011

There are two nonparametric methods that use empirical distribution functions and probability density estimators for the test of the distribution change of data. In this paper we investigate the two methods precisely and summarize the results of previous research. We assume several probability models to make a simulation study of the change point analysis and to examine the finite sample behavior of the two methods. Empirical powers are compared to verify which is better for each model.

• Journal of the Korean Data and Information Science Society
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• v.15 no.3
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• pp.625-632
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• 2004

We consider the empirical Bayes confidence intervals that attain a specified level of EB coverage for the scale parameter in the Burr distribution under type II censoring data. Also, we compare the coverage probabilities and the expected confidence interval lengths for these confidence intervals through simulation study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.374-383
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• 2020

At ship design stage, the maneuverability is generally estimated based on the empirical formula or the computational fluid dynamic (CFD), which is one of the numerical simulation methods. Using the hydrodynamic derivatives derived through these methods can quantitatively estimate the maneuverability of target vessels and evaluate indirect maneuverability. Nevertheless, research on estimating maneuverability is insufficient for ships not subject to IMO maneuverability standard, especially fishing vessels, and even at the design stage, the empirical formula developed for merchant ships is applied without modification. An estimation error may occur due to the empirical formula derived from the regression analysis results of a model test if the empirical formula developed for merchant ships with different hull shapes is applied to fishing vessels without any modification. In this study, the modified empirical formula that can more accurately estimate the fishing vessel's maneuverability was derived by including the hull shape parameter of target fishing trawlers in the regression analysis process that derives Kijima et al. (1990) formula. As a result, the modified empirical formula showed an average estimation error of 6%, and the result improved the average error of 49% of Kijima et al. (1990) formula developed for merchant ships.