• Ocean Science Journal
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• v.41 no.4
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• pp.245-254
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• 2006

Long term wave climate of both extreme wave and operational wave height is essential for planning and designing coastal structures. Since the field wave data for the waters around Korean peninsula is not enough to provide reliable wave statistics, the wave climate information has been generated by means of long-term wave hindcasting using available meteorological data. Basic data base of hindcasted wave parameters such as significant wave height, peak period and direction has been established continuously for the period of 25 years starting from 1979 and for major 106 typhoons for the past 53 years since 1951 for each grid point of the North East Asia Regional Seas with grid size of 18 km. Wind field reanalyzed by European Center for Midrange Weather Forecasts (ECMWF) was used for the simulation of waves for the extra-tropical storms, while wind field calculated by typhoon wind model with typhoon parameters carefully analyzed using most of the available data was used for the simulation of typhoon waves. Design wave heights for the return period of 10, 20, 30, 50 and 100 years for 16 directions at each grid point have been estimated by means of extreme wave analysis using the wave simulation data. As in conventional methodsi of design criteria estimation, it is assumed that the climate is stationary and the statistics and extreme analysis using the long-term hindcasting data are used in the statistical prediction for the future. The method of extreme statistical analysis in handling the extreme vents like typhoon Maemi in 2003 was evaluated for more stable results of design wave height estimation for the return periods of 30-50 years for the cost effective construction of coastal structures.

• Journal of Distribution Science
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• v.11 no.1
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• pp.25-34
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• 2013

Purpose - This study examines the adverse press coverage that has increased in proportion to the remarkable growth of various kinds of franchise businesses in the food service industry. Today, the trust of franchisees in relation to their franchisor, and the maintenance of good relations between the two, has become a significant social issue. This study investigates relationship satisfaction and the long-term commitment between the franchisor and franchisee. Research design, data, methodology - We used a path analysis to investigate the relationship between justice and trust, trust and relationship satisfaction, justice and relationship satisfaction, trust and long-term commitment, and relationship satisfaction and long-term commitment. Structural Equation Modeling and a Sobel test were used to investigate the mediating effects of trust and relationship satisfaction. Data were collected from 237 Food Franchisees in Seoul and Gyeonggi Province in order to test the theoretical model and its hypotheses. Two research methodologies are generally used in the distribution management field. For this study, an empirical method was used. Results - A causal analysis was carried out to test if the research model has a sufficient fit index (for instance, χ² = 46.694, df = 10, p = .000, GFI = 0.946, AGFI = 0.850, RMR = 0.034, NFI = 0.966, CFI = 0.973), and the results showed that the model was sufficient, thus demonstrating the suitability of the research model. Each hypothesis had a positive influence, both on long-term commitment and relationship satisfaction. Justice with the franchisor had a positive influence on trust. Relation satisfaction cognized by franchisees was found to positively influence long-term commitment. The franchisee perception of justice in relation to the franchisor had no significant influence on long-term commitment. The study investigated the hypothesis that trust could mediate justice and long-term commitment, and that relationship satisfaction could also mediate long-term commitment Both trust and relationship satisfaction were found to be important for long-term commitment. Specifically, trust sub-factors and justice sub-factors influenced long-term commitment. Identification-based and knowledge-based trust were more important than calculus-based trust. Distributive justice was deemed more important than procedural justice; distributive justice should thus be strengthened. Conclusions - Both franchisor and franchisee were independent businesses. Evidently however, the franchisor could not ensure profit without long-term commitment from the franchisee. As for the success of the franchise business, the franchisor should carry out appropriate strategies leading to a satisfactory relationship. For example, transparency makes it possible to maintain and enhance trust and to improve relationship satisfaction. Just relations between franchisor and franchisee should make it possible to maintain and enhance the franchisee's trust. The franchisor should provide a variety of information with respect to the franchisee's business success. Finally, in order to improve the franchisee's long-term commitment, the franchisor should ensure a just approach with trust and relationship satisfaction among their strategies.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.413-424
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• 2022

The purpose of this study was attempted to determine the effect of nursing professionalism and self-leadership on long-term work intentions for graduated nursing students. The subjects of this study were 217 graduated nursing students located in W city, and a structured questionnaire was used for the data collection period from November 29 to December 3, 2021. For data analysis, frequency, t-test, one-way ANOVA, Scheffe, Pearson's correlation coefficient, multiple regression using SAS 9.4 program. As a result of the study, the biggest influence factors on the long-term work intention of graduated nursing students were nursing professionalism and major satisfaction, followed by career planning, and explanatory power was 34.3%. Based on the results of this study, it is necessary to develop and operate various programs in the field of nursing education in order to improve the long-term intention of nursing students in graduation year. However, this study is meaningful in that it provided basic data to improve the long-term work intentions of nursing students in graduation year after identifying the level of long-term work intentions and checking factors affecting them.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.252-255
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• 2012

In order to characterize insulation properties of epoxy/micro-silica/nano-silicate composite (EMNC), long-term and short-term AC treeing tests were carried out undr non-uniform electric field generated between needle-plate electrodes. In a long-term test, a 10 kV (60 Hz) electrical field was applied to the specimen positioned between the electrodes with a distance of 2.7 mm in an insulating oil bath at $30^{\circ}C$, and a typical branch type electrical tree was observed in the neat epoxy resin and breakdown took place at 1,042 min after applying the 10 kVelectrical field. Meanwhile, the spherical tree with the tree length of $237{\mu}m$ was seen in EMNC-65-0.3 at 52,380 min (36.4 day) and then the test was stopped because the tree propagation rate was too low. In the short-term test, an electrial field was applied to a 3.5 mm-thick specimen at an increasing voltage rate of 0.5 kV/s until breakdown in insulating oil bath at $30^{\circ}C$ and $130^{\circ}C$, and the data was estimated by Weibull statistical analysis. The electrical insulation breakdown strength for neat epoxy resin was 1,763 kV/mm at $30^{\circ}C$, while that for EMNC-65-0.3 was 2,604 kV/mm, which was a modified value of 47%. As was expected, the breakdown strength decreased at higher test temperatures.

• Journal of Korean Academy of Nursing
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• v.48 no.2
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• pp.167-181
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• 2018

Purpose: We developed and tested the effects of a coping skill training program for caregivers in feeding difficulty among older adults with dementia in long-term care facilities. Methods: A non-equivalent control group pretest-posttest design was used. The subjects comprised 34 caregivers (experimental group: 17, control group: 17) and 40 older adults with dementia (experimental group: 20, control group: 20). The developed program was delivered in 4-hour sessions over 6 weeks (including 2 weeks of lectures and lab practice on feeding difficulty coping skills, and 4 weeks of field practice). Data were collected before, immediately after, and 4 weeks after the program (January 3 to April 6, 2016). The data were analyzed using t-test and repeated measures ANOVA using SPSS/WIN 20.0. Results: Compared to their counterparts in the control group, caregivers in the experimental group showed a significantly greater improvement in feeding knowledge and feeding behavior, while older adults with dementia showed greater improvements in feeding difficulty and Body Mass Index. Conclusion: The study findings indicate that this coping skill training program for caregivers in feeding difficulty is an effective intervention for older adults with dementia in long-term care facilities.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1189-1192
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• 2005

Due to their slow degradation properties, hydrophobic organic contaminants in estuarine sediment have been a concern for risks to human health and aquatic organisms. Studies of fate and transport of these contaminants in estuaries are further complicated by the fact that hydrodynamics and sediment transport processes in these regions are complex, involving processes with various temporal and spatial scales. In order to simulate and quantify long-term attenuation of Polycyclic Aromatic Hydrocarbons (PAH) in the Elizabeth River, VA, we develop a modeling approach, which employs the U.S. Environmental Protection Agency's water quality model, WASP, and encompasses key physical and chemical processes that govern long-term fate and transport of PAHs in the river. In this box-model configuration, freshwater inflows mix with ocean saline water and tidally averaged dispersion coefficients are obtained by calibration using measured salinity data. Sediment core field data is used to estimate the net deposition/erosion rate, treating only either the gross resuspension or deposition rate as the calibration parameter. Once calibrated, the model simulates fate and transport PAHs following the loading input to the river in 1967, nearly 4 decades ago. Sediment PAH concentrations are simulated over 1967-2022 and model results for Year 2002 are compared with field data measured at various locations of the river during that year. Sediment concentrations for Year 2012 and 2022 are also projected for various remedial actions. Since all the model parameters are based on empirical field data, model predictions should reflect responses based on the assumptions that have been governing the fate and sediment transport for the past decades.

• Wind and Structures
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• v.17 no.1
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• pp.43-68
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• 2013

The fluctuating wind induced vibration is one of the most important factors which has been taken into account in the design of long-span bridge due to the low stiffness and low natural frequency. Field measurement characteristics of sustained wind on structure site can provide accurate wind load parameters for wind field simulation and structural wind resistance design. As a suspension bridge with 1490 m main span, the Runyang Suspension Bridge (RSB) has high sensitivity to fluctuating wind. The simultaneous and continuously wind environment field measurement both in mid-span and on tower top is executed from 2005 up to now by the structural health monitoring system installed on this bridge. Based on the recorded data, the wind characteristic parameters, including mean wind speed, wind direction, the turbulence intensity, the gust factors, the turbulence integral length, power spectrum and spatial correlation, are analyzed in detail and the coherence functions of those parameters are evaluated using statistical method in this paper. The results indicate that, the turbulence component of sustain wind is larger than extremely strong winds although its mean wind speed is smaller; the correlation between turbulence parameters is obvious; the power spectrum is special and not accord with the Simiu spectrum and von Karman spectrum. Results obtained in this study can be used to evaluate the long term reliability of the Runyang Suspension Bridge and provide reference values for wind resistant design of other structures in this region.

• Journal of Astronomy and Space Sciences
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• v.25 no.2
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• pp.71-76
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• 2008

Study of terrestrial impact craters is important not only in the field of the solar system formation and evolution but also of the Galactic astronomy. The terrestrial impact cratering record recently has been examined, providing short- and intermediate-term periodicities, such as, ${\sim}26$ Myrs, ${\sim}37$ Myrs. The existence of such a periodicity has an implication in the Galactic dynamics, since the terrestrial impact cratering is usually interpreted as a result of the environmental variation during solar orbiting in the Galactic plane. The aim of this paper is to search for a long-term periodicity with a novel method since no attempt has been made so far in searching a long-term periodicity in this research field in spite of its great importance. We apply the cepstrum analysis method to the terrestrial impact cratering record for the first time. As a result of the analysis we have found noticeable peaks in the Fourier power spectrum appear ing at periods of ${\sim}300$ Myrs and ${\sim}100$ Myrs, which seem in a simple resonance with the revolution period of the Sun around the Galactic center. Finally we briefly discuss its implications and suggest theoretical study be pursued to explain such a long-term periodicity.

• Smart Structures and Systems
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• v.32 no.5
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• pp.297-308
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• 2023

Dynamic deflection is important for evaluating the performance of a long-span cable-stayed bridge, and its continuous measurement is still cumbersome. This study proposes a dynamic deflection monitoring method for cable-stayed bridge based on Bi-directional Long Short-term Memory (BiLSTM) neural network taking advantages of the characteristics of spatial variation of cable acceleration response (CAR) and main girder deflection response (MGDR). Firstly, the relationship between the spatial and temporal variation of the CAR and the MGDR is described based on the geometric deformation of the bridge. Then a data-driven relational model based on BiLSTM neural network is established using CAR and MGDR data, and it is further used to monitor the MGDR via measuring the CAR. Finally, numerical simulations and field test are conducted to verify the proposed method. The root mean squared error (RMSE) of the numerical simulations are less than 4 while the RMSE of the field test is 1.5782, which indicate that it provides a cost-effective and convenient method for real-time deflection monitoring of cable-stayed bridges.

• Journal of Computing Science and Engineering
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• v.5 no.2
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• pp.150-160
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• 2011

Automatic text classification has a long history and many studies have been conducted in this field. In particular, many machine learning algorithms and information retrieval techniques have been applied to text classification tasks. Even though much technical progress has been made in text classification, there is still room for improvement in text classification. In this paper, we will discuss remaining issues in improving text classification. In this paper, three improvement issues are presented including automatic training data generation, noisy data treatment and term weighting and indexing, and four actual studies and their empirical results for those issues are introduced. First, the semi-supervised learning technique is applied to text classification to efficiently create training data. For effective noisy data treatment, a noisy data reduction method and a robust text classifier from noisy data are developed as a solution. Finally, the term weighting and indexing technique is revised by reflecting the importance of sentences into term weight calculation using summarization techniques.