• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.259-264
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• 2006

The purpose of this study is to suggest logical foundation and points which necessarily for establishing E-commerce of Korean shipping companies' development strategy and activation plan. In order to empirical analysis, two step analyses are adopted. Firstly, this study examines the effects of the shipping company character and the shipping environment character on the usage of E-commerce in the shipping companies. Secondly, this study examines the effects of usage of E-commerce on the performance in shipping companies. In the empirical analysis, research hypotheses are being tested mainly by a structural equation model(SEM).

• Korean Journal of Materials Research
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• v.31 no.5
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• pp.255-263
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• 2021

P91 steel has been a highly researched material because of its applicability for high-temperature applications. Considerable efforts have been made to produce experimental creep data and develop models for creep life prediction. As creep tests are expensive and difficult to conduct, it is vital to develop authenticated empirical methods from experimental results that can be utilized for better understanding of creep behavior and can be incorporated into computational models for reliable prediction of creep life. In this research, a series of creep rupture tests are performed on the P91 specimens within a stress range of 155 MPa to 200 MPa and temperature range of 640 ℃ (913 K) to 675 ℃ (948 K). The microstructure, hardness, and fracture surfaces of the specimens are investigated. To analyze the results of the creep rupture tests at a macro level, a parameter called creep work density is derived. Then, the relationships between various creep parameters such as strain, strain rate, time to rupture, creep damage tolerance factor, and creep work density are investigated, and various empirical equations are obtained.

• Proceedings of the Korea Hospitality Industry Research Society Conference
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• 2005.11a
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• pp.1-20
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• 2005

Family Restaurant is a service business of a kind. The role of service operator is to improve a sales of service goods through maximizing the service value with customer satisfaction at the moment of MOT(moment of truth). Family Restaurant come to the great growth on the face of it. In future, it will place emphasis more and more on not hardware but software including service quality. The purpose of this study, therefore, is to research the effect on service quality of the job satisfaction of Family Restaurant's service staff. Data was collected from the employee who are working at Family Restaurant located in Taegu. The empirical research has been done over 50days from 1April, 2004 to 20May, 2004. In conclusion of empirical analysis, 4 hypotheses were significant among 7 hypotheses suggested in this study. The research showed as follows : First, the organic trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed positive influence on job satisfaction. Second, the personal trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed positive influence on service quality. Third, the official trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed negative influence on job satisfaction. Fourth, the organic trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed positive influence on service quality. Fifth, the personal trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed negative influence on service quality. Sixth, the organic trait among the effect factor of job satisfaction perceived by Family Restaurant service staff showed negative influence on service quality. Seventh, the job satisfaction of Family Restaurant service staff showed positive influence on service quality. Besides, the critical points of this study are as follows; First, we designated the subject of research to the employee of Family Restaurant only. Second, multi-situations(time, holiday) which can happen as service was offered, wasn't concerned. Third, as service quality was estimated by general service quality. the research in future should subdivide service quality more. I. finally, applied the pervious researches on job satisfaction and service quality in the employee of Family Restaurant. To extend more this research model in future, the variables like customer satisfaction should be added.

• Asia Pacific Journal of Business Review
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• v.1 no.2
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• pp.37-62
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• 2017

To analyze the effects of R&D expenditure on the firm value of Korean firms, we classified portfolios based on R&D activity levels. After that, we conducted a time-series analysis to assess excess returns from the portfolios. To carry out such an analysis, an empirical analysis of excess returns in the capital market was performed by using the monthly earning rate of stocks from 2000 to 2013. The purpose of this research is to provide basic data on investment to stakeholders in the capital market by analyzing the effects of R&D on the firm value and to overcome scholarly limitations by offering a new model of analysis. The criteria for classifying the portfolios were based on R&D expenditure levels. The analysis models follow the Fama-French Three-Factor Model and the Carhart Four-Factor Model. The analyses results are as follows. Extrapolating monthly profit rates based on R&D expenditure levels, portfolios with low R&D expenditures showed higher earning rates than those with high R&D expenditures. This suggests that high R&D expenditures did not translate into high earning rates. The investor depreciates the R&D expenditures related profitability and the possibility of success in the market, leading to falls in stock prices and a failure to give a positive effect on the firm value. Our research differs from the previous investigations as we carried out an empirical analysis based on the actual investors' attitudes about R&D expenditures and how these can generate excess earnings. Our research results show that the data related to R&D expenditure are not reflected fully in the market.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.33-40
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• 2020

It is now common to find the wastes buried in the past during the excavation process of soil for large scale housing and land development. Without proper treatment of the wastes environmentally, the excavation process is no longer able to proceed, and an action plan should be provided to treat the wastes with environmental and economic viability. In the study, the relationship between the apparent density of the wastes and the volume conversion factor, which is the basis in the estimation of waste treatment cost was investigated. From 10 sampling points of a landfill site, wastes were sampled, analyzed for physical characteristics, and the apparent density of mixed and sorted waste was assessed. Applying the empirical formula, and the formula we suggested here, the volume conversion factors were compared with that measured directly in the field using dump truck and excavator. Obviously there was a close relationship among the volume conversion factors resulting from the empirical formula, the formula we suggested and that measured in the field.

• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.490-497
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• 2018

In this study, we examined whether common idiosyncratic volatility(CIV), a risk factor for idiosyncratic volatility, can be evaluated as a pricing factor. The sample is listed on the Korea Exchange. The analysis period is 288 months from July 1992 to June 2016. The main results of this study are as follows. First, in the empirical verification of the market excess returns of the testing portfolios, the difference in the return on the CIV factor sensitivity difference was statistically significant. In other words, we confirmed that there is a risk premium for CIV factors. Second, CAPM, FF3 factor model, and FF5 factor model do not explain the risk premium for CIV factors, whereas factor models that add CIV factors explain the risk premium for CIV factors. In other words, the CIV factor can be evaluated in terms of pricing factors.

• Journal of Labour Economics
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• v.28 no.1
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• pp.61-82
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• 2005

We investigate wage differentials in Korea in the manufacturing industry, as well as factors affecting structural change in wage determination for the pre- and post-financial crisis regimes. We use the 1995 and 1999 data from the Survey Report on the Wage Structure (SRWS) from the Ministry of Labor. Principal components regression analysis is used to tackle multicollinearity. We employ factor analysis to reduce a set of variables to a smaller number, which contain observed and latent variables. Our empirical investigation provide evidences for changes in wages structure between 1995 and 1999. In 1995, the job quality factor is the most critical in the determination of wages, while in 1999, the industry attributes factor impacts greatly on the wages.

• English Language & Literature Teaching
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• v.17 no.1
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• pp.191-208
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• 2011

The quantitative study investigated perceptions of evaluative criteria in L2 writing between two groups - learners (N=212) and instructors (N=52) in Korea. Specifically, the purpose of the study is (1) to examine learners' and instructors' perceptions on evaluative criteria in L2 writing and to provide empirical evidence concerning how they respond to a list of them and (2) to ultimately devise appropriate rating criteria applicable to an EFL context like Korea. Analyses of evaluative criteria were conducted using factor analysis and yielded the following results: learner and instructor groups perceived the evaluative criteria differently and weighted them in a different way. For the learner group, the combined elements of grammar and language in use were identified as Factor 1 and mechanics as Factor 2. The results may infer that learners' response patterns are primarily linked to their instructors' writing practice in class, which may largely focus on grammatical knowledge based on lexical use and mechanical accuracy. Similarly, the instructor group acknowledged grammatical knowledge as Factor 1 and lexical use as Factor 2. The first two factors found in both learner and instructor groups indicate that in an EFL context like Korea, the form-then-content way of teaching and learning is still being considered more effective in L2 writing than any other method. Taking into consideration these perceptive similarities and differences between learners and instructors, the categories of evaluative criteria in writing include content and organization, grammar, mechanics, language in use, and flow of the essay, respectively.

• The Korean Journal of Applied Statistics
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• v.25 no.5
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• pp.829-835
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• 2012

When the input features are generated by factors in a classification problem, it is more meaningful to identify important factors, rather than individual features. The $F_{\infty}$-norm support vector machine(SVM) has been developed to perform automatic factor selection in classification. However, the $F_{\infty}$-norm SVM may suffer from estimation inefficiency and model selection inconsistency because it applies the same amount of shrinkage to each factor without assessing its relative importance. To overcome such a limitation, we propose the adaptive $F_{\infty}$-norm ($AF_{\infty}$-norm) SVM, which penalizes the empirical hinge loss by the sum of the adaptively weighted factor-wise $L_{\infty}$-norm penalty. The $AF_{\infty}$-norm SVM computes the weights by the 2-norm SVM estimator and can be formulated as a linear programming(LP) problem which is similar to the one of the $F_{\infty}$-norm SVM. The simulation studies show that the proposed $AF_{\infty}$-norm SVM improves upon the $F_{\infty}$-norm SVM in terms of classification accuracy and factor selection performance.

• Steel and Composite Structures
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• v.28 no.2
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• pp.209-221
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• 2018

An empirical and efficient method is presented for calculating the dynamic increase factor to amplify the applied loads on the affected bays of a steel frame structure with semi-rigid connections. The nonlinear static alternate path analysis is used to evaluate the dynamic responses. First, the polynomial models of the extended end plate and the top and seat connection are modified, and the proposed polynomial model of the flush end plate connection shows good agreement as compared with experimental results. Next, a beam model with nonlinear spring elements and plastic hinges is utilized to incorporate the combined effect of connection flexibility and material nonlinearity. A new step-by-step analysis procedure is established to obtain quickly the dynamic increase factor based on a combination of the pushdown analysis and nonlinear dynamic analysis. Finally, the modified dynamic increase factor equation, defined as a function of the maximum ratio value of energy demand to energy capacity of an affected beam, is derived by curve fitting data points generated by the different analysis cases with different column removal scenarios and five types of semi-rigid connections.