• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3B
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• pp.175-183
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• 2012

In this study, Galerkin scheme and SU/PG scheme of Petrov-Galerkin family were applied to the shallow water equations and a finite element model for shallow water flow was developed. Numerical simulations were conducted in several flumes with convection-dominated flow condition. Flow simulation of channel with slender structure in the water course revealed that Galerkin and SU/PG schemes showed similar results under very low Fr number and Re number condition. However, when the Fr number increased up to 1.58, Galerkin scheme did not converge while SU/PG scheme produced stable solutions after 5 iterations by Newton-Raphson method. For the transcritical flow simulation in diverging channel, the present model predicted the hydraulic jump accurately in terms of the jump location, the depth slope, and the flow depth after jump, and the numerical results showed good agreements with the hydraulic experiments carried out by Khalifa(1980). In the oblique hydraulic jump simulation, in which convection-dominated supercritical flow (Fr=2.74) evolves, Galerkin scheme blew up just after the first iteration of the initial time step. However, SU/PG scheme captured the boundary of oblique hydraulic jump accurately without numerical oscillation. The maximum errors quantified with exact solutions were less than 0.2% in water depth and velocity calculations, and thereby SU/PG scheme predicted the oblique hydraulic jump phenomena more accurately compared with the previous studies (Levin et al., 2006; Ricchiuto et al., 2007).

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1331-1334
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• 2004

Wet/Dry phenomena typically incorporate a number of complex flow mechanism. These include a momentum transfer and turbulent mixing caused by the delivery of water. However currently available one dimensional schemes applicable to wet/dry process cannot effectively simulate such process. Two dimensional finite element model, SU/PG, is used to simulate complex flow in this study. The Wetted Area Method in SU/PG allows elements to transition gradually between wet and dry states. The model is applicable to a straight river reach with irregular bathymetry. Wet/dry calculation using the wetted area method can simulate simple numerical test. The computed results of velocity vectors and water depth agree with those of observed. The methodology Presented in this study will contributed to two-dimensional wet/dry analysis in a river in this country.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.198-198
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• 2011

The numerical simulation of dam break problem suffers from several challenges in terms of accuracy, stability, and versatility of the simulation algorithm since the water flow is generally discontinuous and presents abrupt variations. Thus, to obtain stable and accurate solutions, flow models for this purpose require numerical schemes provided with shock-capturing properties, and with the ability to work with flexible two-dimensional meshes. In this context, SU/PG method(Hughes and Brooks, 1979) is excellent candidate for the solution of the dam break problem. The weak formulation of the equations and the discontinuous polynomial basis lead to an accurate representation of bore waves(shocks). Furthermore, the discretization of the domain in finite elements is extremely effective in modeling complex geometries. In this study, a finite element model based on the SU/PG scheme is developed to solve shallow water equations and the model is applied to dam break problem. It is found that the present model accurately captures the bore wave that propagates downstream while spreading laterally and the depression wave that moves upstream. Furthermore, the propagation and formation of water surface profile compared favorably with those obtained by the previously published results.

• ETRI Journal
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• v.8 no.3
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• pp.3-14
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• 1986

Currently, CIF is used widely as a common data base to represent IC layouts. The CIF2PG program is developed using C language to obtain electromask or mann 3000 PG file from the CIF input file. By obtaining the PG data, which can realize the actual mask layout, the construction of IC Design Automation System became possible using a general purpose computer.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.5
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• pp.431-440
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• 2019

Purpose: No national survey has yet described the guidelines followed by Korean pediatricians to treat acute gastroenteritis (AGE). An online survey was performed to investigate the management of AGE followed by members of The Korean Society of Pediatric Gastroenterology, Hepatology, and Nutrition, and the results were compared between pediatric gastroenterologists (PG) and general pediatricians (GP). Methods: Questionnaires were sent to pediatricians between June 2 and 4, 2018 regarding the type of hospital, indications for admission, antiemetic and antidiarrheal drugs and antibiotics prescribed, and dietary changes advised. Results: Among the 400 pediatricians approached, 141 pediatricians (35.3%) responded to the survey. PG comprised 39% of the respondents and 72.7% worked at a tertiary hospital. Both PG and GP considered diarrhea or vomiting to be the primary symptom. The most common indication for hospitalization was severe dehydration (98.8%). Most pediatricians managed dehydration with intravenous fluid infusions (PG 98.2%, GP 92.9%). Antiemetics were prescribed by 87.3% of PG and 96.6% of GP. Probiotics to manage diarrhea were prescribed by 89.1% of PG and 100.0% of GP. Antibiotics were used in children with blood in diarrheal stool or high fever. Dietary changes were more commonly recommended by GP (59.3%) than by PG (27.3%) (p<0.05). Tests to identify etiological agents were performed primarily in hospitalized children. Conclusion: This survey assessing the management of pediatric AGE showed that the indications for admission and rehydration were similar between GP and PG. Drug prescriptions for diarrhea and dietary changes were slightly commonly recommended by GP than by PG.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.839-846
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• 2006

This study was conducted to evaluate the effects of dietary addition of sucrose, propylene glycol and Tween 80 (Polysorbate 80 : Non-ionic Surfactants) on pre-partum (21 d) and post-partum (21 d) nutrients intake, blood metabolites, occurrence of metabolic disorders, milk yield and its composition in Holstein cows. Two basal diets were formulated each for pre- and post-partum period. The diets were mixed daily and fed at ad libitum to transitional cows. Forty cows of similar parity and milk yield were randomly divided into four groups (ten animals in each). The cows in three groups were supplemented either with 280g of sucrose/day (SU), SU+64g propylene glycol/day (SUP) or SUP+50g Tween80/day (SUPT). The feed for the fourth group was not supplemented and this group served as control (C). Pre-partum DM, total digestible nutrients (TDN), and crude protein (CP) intake was similar in cows fed C, SU, SUP, and SUPT diets. Post-partum DM, TDN, and CP intakes were the highest with SUPT diet followed by SU, SUP and control diets. Pre-partum blood non-esterified fatty acids (NEFA) concentration was noticed significantly higher in cows fed control diet compared to those fed SU, SUP and SUPT diets. The concentration of NEFA was similar at calving and during post-partum period across cows fed different experimental diets. Blood glucose and Ca concentration during pre- and post-partum periods were not significantly different in cows fed C, SU, SUP and SUPT diets. Milk yield (kg/day) was similar in cows fed different experimental diets. However, milk fat percent and 4% fat corrected milk yield were higher in cows fed SU diet (p<0.05) followed by SUP, SUPT and C diets. One case of ketosis was recorded in cows fed control diet however its occurrence was not observed in cows fed other diets. Occurrence of retained placenta and mastitis was numerically higher in cows fed control diet compared with those fed SU, SUP and SUPT diets. In conclusion, the NIS and propylene glycol feeding along with sucrose could improve the 4% fat corrected milk and fat yield in early lactating cows with significant reduction in NEFA and metabolic disorders during transitional period.

• Proceedings of the Korea Water Resources Association Conference
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• 2003.05a
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• pp.485-488
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• 2003

• TTA Journal
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• s.128
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• pp.77-81
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• 2010

• TTA Journal
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• s.146
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• pp.57-60
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• 2013

• TTA Journal
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• s.144
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• pp.59-64
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• 2012