• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.2
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• pp.100-108
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• 1998

Morison formula has been used in the determination of wave forces acting on vertical cylindrical piles of ocean structures. The formula, however, can be applied to mildly varying varying incident waves with symmetrical shapes. The breaking waves impinge on structures with very high impact forces, which completely differ from the inertia and drag forces of the Morison formula in both magnitudes and characteristics. In the present study, a boundary element method is applied to determine the water particle velocity and acceleration under the breaking waves. A numerical model is then developed to determine breaking wave forces utilizing those water particle kinematics. The results of the model is then developed to determine breaking wave forces utilizing those water particle kinematics. The results of the model agree well with existing experimental data, giving maximal wave forces 3 times and maximal moments 5 times larger than the Morison formula does.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.115-127
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• 2015

The aim of this study is to develop a simplified formula for added mass coefficients of a two-dimensional floating body moving vertically in a finite water depth. Floating bodies with various sectional areas may represent simplified structure sections transformed by Lewis form, and can be used for floating body motion analysis using strip theory or another relevant method. Since the added mass of a floating body varies with wave frequency and water depth, a correction factor is developed to take these effects into account. Using a developed two-dimensional numerical wave tank technique, the reference added masses are calculated for various water depths at high frequency, and used them as basis values to formulate the correction factors. To verify the effectiveness of the developed formulas, the predicted heave added mass coefficients for various wetted body sections and wave frequencies are compared with numerical results from the Numerical Wave Tank (NWT) technique.

• Journal of the Korean Ceramic Society
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• v.55 no.1
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• pp.67-73
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• 2018

A poled lead zirconate titanate (PZT) cube specimen that is switched by an electric field at room temperature is subject to temperature increase. Changes in polarization and thermal expansion coefficients are measured during temperature rise. The measured data are analyzed to obtain changes in pyroelectric coefficient and strain during temperature change. Empirical formulae are developed using linear or quadratic curve fitting to the data. The nonlinear behavior of the materials during temperature increase is predicted using the developed formulae. It is shown that the calculation results can be compared successfully with the measured values, which proves the accuracy and reliability of the developed formulae for the nonlinear behavior of the materials during temperature changes.

• Journal of Dairy Science and Biotechnology
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• v.23 no.2
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• pp.155-160
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• 2005

Many countries divide infant formula into special nutrient food and they are in control of thorn very carefully. CODEX prescribes that the components which can be added to infant formula must be exist in the breast milk and the additives must be scientifically proved to be safe. Therefore infant formula manufacturers make efforts to develop infant formula to be similar to human milk based on research of human and bovine milk components. Domestic infant formulas are rich with functional components in comparison with foreign formulas ; such as immunity, anti-allergy, growth factor, developments of brain and digestion organs etc. At this point, progress of bioscience technology and introduction of various new technologies lead micro components in human and bovine milk to be separated and purified. Therefore many functional components are commercialized and infant formula companies use these. Various functional components are added to infant formula ; DHA and arachidonic acid as brain growth components, nucleotide and lactoferrin as immunity increment and oligosaccharides fur digestion. And new infant formula is being developed by using bone growth factor and dehydration components f3r atopy and allergy decrement.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.6
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• pp.72-82
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• 2000

Many lot of books introduce the methods to calculate the time of concentration, and these are described as various forms of formulas. There are few formulas appropriate for our basin characteristics Therefone, there are problems to make excessive or less estimation when these formulas are used. To solve these problems, comparison of formulas and sensitivity analysis for them were made with converting parameters. Finally, Time of concentration was estimated to derive Application limits for 3 watersheds by standardized formulas. In the case of input parameters analysis, SCS formula has the highest value by the length, Kerby by the height and SCS by the slope, respectively, while Kraven formula has the lowest value among them. Concerning the relative sensitivity by Taylor series, the time of concentration showed the constant effect while increasing of the length and slope, and the length was more sensitive than the slope in parameters. Finally the standardization formula developed in this study was applied to derive application limits for 3 watersheds(total 17 subbasins). In this case, Rziha(8 subbasins) and SCS(9 subbasins) formulas were the most similar to observed data of total 17 subbasins respectively. Application limits were about 300~500$\textrm{km}^2$ area, 30~60km length and under 0.01 slope for Rziha formula and about 100~200$\textrm{km}^2$ area, 10~30km length, and over 0.01 slope for SCS formula, respectively.

• Child Health Nursing Research
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• v.22 no.2
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• pp.79-86
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• 2016

Purpose: The purpose of this study was to identify breastfeeding practice with late preterm infants (LPIs), and to determine predictors of exclusive breastfeeding at the 12th week after discharge. Methods: The participants were 106 mothers of LPIs hospitalized in neonatal intensive care units at two university hospitals. Data were collected between February and October, 2013. Questionnaires included characteristics of LPIs, their mothers, and feeding-related characteristics. Feeding methods were exclusive breastfeeding, mixed feeding, and formula feeding. Results: Exclusive breastfeeding steadily increased from 5.7% at the 1st week to 19.8% at the 12th week, as did formula feeding from 27.3% to 67.9%. Contrarily, mixed feeding decreased from 67.0% at the 1st week to 12.3% at the 12th week. The ratio of formula feeding was higher than that of exclusive breastfeeding over time. Predictors for exclusive breastfeeding were the following: type of delivery (OR=2.96, 95%CI=1.07-8.14), feeding intolerance (OR=3.03, 95%CI=1.26-7.25) and feeding method during hospitalization (OR=7.84, 95%CI=3.15-19.53). Conclusion: In order to increase breastfeeding opportunities for LPIs, educational programs for gestational age-appropriate breastfeeding should be developed. The focus of breastfeeding education needs to be on mothers who delivered their LPIs through Cesarean-section and LPIs who had feeding intolerance or were fed only formula during hospitalization.

• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.321-328
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• 2018

In clinical trials with repeated measurements, the time-averaged difference (TAD) may provide a more powerful evaluation of treatment efficacy than the rate of changes over time when the treatment effect has rapid onset and repeated measurements continue across an extended period after a maximum effect is achieved (Overall and Doyle, Controlled Clinical Trials, 15, 100-123, 1994). The sample size formula has been investigated by many researchers for the evaluation of TAD in two treatment groups. For the evaluation of TAD in multi-arm trials, Zhang and Ahn (Computational Statistics & Data Analysis, 58, 283-291, 2013) and Lou et al. (Communications in Statistics-Theory and Methods, 46, 11204-11213, 2017b) developed the sample size formulas for continuous outcomes and count outcomes, respectively. In this paper, we derive a sample size formula to evaluate the TAD of the repeated binary outcomes in multi-arm trials using the generalized estimating equation approach. This proposed sample size formula accounts for various correlation structures and missing patterns (including a mixture of independent missing and monotone missing patterns) that are frequently encountered by practitioners in clinical trials. We conduct simulation studies to assess the performance of the proposed sample size formula under a wide range of design parameters. The results show that the empirical powers and the empirical Type I errors are close to nominal levels. We illustrate our proposed method using a clinical trial example.

• English Language & Literature Teaching
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• v.18 no.3
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• pp.1-24
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• 2012

It has long been shown that Korean EFL students have not practiced extensive reading in school curriculum. Their vocabulary knowledge is limited and a tool for measuring text readability for them has hardly been developed and used. The study aimed to check the current situations on the above issues and develop a reading framework appropriate for extensive reading within the national English curriculum, including the Readability Formula in Korean EFL contexts (KRF). The study consists of four steps. The study does a survey to check the current Korean EFL situations on the issues, suggests a new vocabulary learning size, develops a readability formula as a tool for measuring text difficulty based on the newly suggested vocabulary size, and finally validates the formula with various kinds of English books, including the primary and secondary school English textbooks. It is expected that this study will provide a model for the vocabulary size and the readability index for extensive reading in EFL contexts.

• The Journal of Korean Medical History
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• v.34 no.2
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• pp.65-77
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• 2021

Lee Jema said in his book, Dongui Susebowon, that the prescriptions for Soum constitutional type were already developed by doctors during the Song Jin Yuan China around 10th-13th century. Those prescriptions were common techniques that were used throughout the East Asian region. Among them, Lee Jema specially selected some candidate formulas and modified them according to his constitutional theory. This study investigated how similar his modified prescriptions to original formulas through database[ancient formula database] analysis. 24 out of 24 Soum prescriptions selected meaningful ingredient herbs from the original formula. A 50% or higher concordance rate compared to the original formulas. There are only 9 treatment prescriptions that cannot be checked in the ancient formula database. A future task will be to reveal the practical meanings of the ingredients Lee Jema adjusted for the Soum constitutional type patients.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.246-255
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• 2021

Most fishing vessels are less than 100 m in length (LBP), which is not mandatory for the IMO standards for ship maneuverability. Therefore, research on estimating the maneuverability of fishing vessel hull shapes are somewhat lacking compared to that of merchant ship hull shapes, and at the design stage, the numerical simulation method developed for merchant ships are applied without modification to estimate the maneuverability. Since this can cause estimation errors, the authors have derived a modified empirical formula that can improve the accuracy of estimating the maneuverability of fishing vessels in a previous study. In this study, using the modified empirical formula, the IMO maneuverability evaluation items, the turning motion test and Z-test simulations were performed on the fisheries training vessel BAEK-KYUNG and compared with the sea trial test result to verify the validity of the modified empirical formula. In conclusion, the modified empirical formula was able to estimate quantitatively and qualitatively similar to the result of the sea trial test. Such a study on estimating the maneuverability of fishing vessels will be a good indicator for fishing vessel operators and will help them analyze marine accidents.