• 한국항해항만학회지
• /
• 제36권4호
• /
• pp.291-298
• /
• 2012

Working onboard large ocean-going vessels is one of many industries that is by its very nature extremely error-provoking. In industries such as aviation, nuclear power, healthcare and transport, the need for mental preparedness and professionalism are amongst the qualities essential for the management of complex hazardous systems. Recruiting, training, and more importantly retaining the right people to work in these industries is of paramount importance if safety is to be continuously improved and economic benefits realized. Through consideration of extant empirical literature this paper will explore the need for enhancing collaboration between shipping companies and maritime training insitutes in order to provide the industry with those most capable for the job. It will be concluded that by providing a strong maritime foundation from the outset of training, maritime academies in South Korea can provide shipping companies with a wealth of highly qualified, motivated officers who will contribute to safety and remain valuable assets within the industry for years to come.

• 설비공학논문집
• /
• 제24권1호
• /
• pp.85-89
• /
• 2012

This study has been conducted to compare two cargo handling systems on MR tanker and Panamax tanker. Submerged hydraulic cargo pumps with hydraulic power packs and frequency converter controlled electric deepwell pumps will be investigated and compared on all aspects of initial cost, installation, operation and maintenance. The result of investigation shows Electric Systems have less manufacturing costs, higher environmental friendliness and reliable operation compare to Hydraulic Systems. Furthermore, the present experimental data will provide important database for Electric Systems onboard new ships and practical and empirical guidelines are constructed for further determine the design of the Electric Systems.

• Journal of Information Technology Applications and Management
• /
• 제18권4호
• /
• pp.131-148
• /
• 2011

Our work empirically investigates the cultural differences of Social Networking Service (SNS) users in China, Korea and U.S. We construct a survey questionnaire from existing literature and test it for reliability, validity, and model fit. Then we collect data and validate the cultural differences of SNS users in three nations. Our results show different rankings from existing literature in cultural dimensions about three nations. In terms of masculinity, we find China > U.S. > Korea, similar to Hofstede. In individualism, we find U.S. > Korea > China, different from Hofstede (U.S. > China > Korea). In power distance, it is shown that Korea > China > U.S., different from Hofstede (China > Korea > U.S.). Uncertainty avoidance is found that U.S. > Korea > China, lowered ranking of Korea from the top among three nations in Hofstede. We find that these outcomes would be useful in updating national culture of the three nations and for future research about cultural impacts on SNS adoption.

• Industrial Engineering and Management Systems
• /
• 제12권4호
• /
• pp.406-415
• /
• 2013

The present study examines a set of financial ratios in predicting the up or down movements of stock prices in the context of a securities law, the Sarbanes-Oxley Act of 2002 (SOA), controlling for macroeconomic variables. Using the logistic regression with proxy betas to alleviate the incompatibility problem between the firm-specific financial ratios and macroeconomic indicators, we report evidence that financial ratios are meaningful predictors of stock price changes, which subdue the influence of macroeconomic indicators on stock returns, and more importantly that the SOA truly improves the stock price predictability of financial ratios for the markup sample. The empirical results further suggest that industry and time effects exist and that for the markdown sample the SOA actually deteriorates the predictive power of financial ratios.

• Wind and Structures
• /
• 제9권6호
• /
• pp.419-440
• /
• 2006

This article synthesizes the literature on the meteorology, experimental simulation, and wind engineering ramifications of intense downburst outflows. A novel design of a large-scale test facility and experimental evidence of its validity are presented. A two-dimensional slot jet is used to simulate only the outflow region of a downburst. Profiles of mean velocity and turbulence quantities are acquired using hot-wire anemometry. Comparison with the literature provides empirical evidence that supports the current approach. A geometric analysis considers the validity of applying a two-dimensional approximation for downburst wind loading of structures. This analysis is applicable to power transmission lines in particular. The slot jet concept can be implemented in a large boundary layer wind tunnel to enable large-scale laboratory experiments of thunderstorm wind loads on structures.

• Communications for Statistical Applications and Methods
• /
• 제14권1호
• /
• pp.241-254
• /
• 2007

This paper propose a new short-term interest rate model having a different nonlinear drift function and the same diffusion coefficient with Chan et al. (1992) model. The fractional polynomial power of the drift function in our model is linked to the local volatility elasticity of the diffusion coefficient. While the nonlinear drift function estimated by $A\"{\i}t$-Sahalia (1996a) and others has a feature that higher interest rates tend to revert downward and low rates upward, the drift function estimated by our nonlinear model shows that higher interest rate mean-reverts strongly, but, medium rates has almost zero drift and low rates has a very small drift. This characteristic coincides the empirical result based on the nonparametric methodology by Stanton (1997) and the implication by the scatter plot of the short rate data.

• Journal of the Korean Data and Information Science Society
• /
• 제7권1호
• /
• pp.37-46
• /
• 1996

계단충격가속수명시험에서 얻은 자료를 토대로 통계적 추론을 위해 가정하는 수명분포에 대한 적합도 검정을 Kolmogorov-Smirnov, Cramer-von Mises, Anderson-Darling과 같은 비모수적 검정통계량들을 이용한 검정절차를 제안하고, 각 통계량들을 검정력 측면에서 비교하고자 한다.

• 대한기계학회논문집A
• /
• 제25권1호
• /
• pp.1-10
• /
• 2001

As computer power is increased, refined finite element models are employed for structural analysis. However, it is difficult and expensive to use refined models in the design stage. The refined models especially cause problems in the preliminary design where the design is frequently changed. Therefore, simplified models are needed. The simplification process is regarded as an empirical technique. Simplified and equivalent finite element model of a structure has been studied and used in the preliminary design. A general approach to establish the simplified and equivalent model is presented. The generated simple model has satisfactory correlation with the corresponding refined finite element model. An optimization method, the Goal Programming algorithm is used to make the simple model. The simplified model is used for the design change and the changed design is recovered onto the original design. The presented method was verified with three examples.

• Journal of the Korean Statistical Society
• /
• 제26권1호
• /
• pp.101-116
• /
• 1997

This is primarily an expository paper that presents several nonparametric procedures for testing exponentiality against certain monotonicity properties of the mean residual life function, tests against the trend change in such function attract a great deal of attention of late in reliability analysis. In this note, we present some of the known testing procedures regarding the behavior of mean residual life function. These tests are also compared in terms of asymptotic relative efficiency and empirical power against a few alternatives. The tests based on incomplete data are also briefly discussed.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2006년도 학술발표회 논문집
• /
• pp.1450-1454
• /
• 2006

Empirical mode decomposition (EMD) is applied to analyze time series characterized with nonlinearity and nonstationarity. This decomposition could be utilized to construct finite and small number intrinsic mode functions (IMF) that describe complicated time series, while admitting the Hilbert transformation properties. EMD has the capability of being adaptive, capture local characteristics, and applicable to nonlinear and nonstationary processes. Unlike discrete wavelet transform (DWT), IMF eliminates spurious harmonics and retains meaningful instantaneous frequencies. Examples based on data representing natural phenomena are given to demonstrate highlight the power of this method in contrast and comparison of other ones. A presentation of the energy-frequency-time distribution of these signals found to be more informative and intuitive when based on Hilbert transformation.