• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.357-361
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• 2011

The terminal current in voltage driven systems is an essential role for characterizing the pattern of electric discharge such as corona, breakdown, etc. Until now, to evaluate this terminal current, Sato's equation has been widely used in areas of high voltage and plasma discharge. Basically Sato's equation was derived by using the energy balance equation and its final form described physical meaning explicitly. To give more general abilities in Sato's equation, we present a generalized approach by directly using the Poynting's theorem incorporating the finite element method. When the magnetic field effect or the time-dependent voltage source is considered, this generalized energy method can be easily applicable to those problems with any dielectric media such as gas, fluid, and solid. As an alternative approach, the integral Ohm's law resulting in small numerical errors has an ability to be applied to multi-port systems. To test the generalized energy method and integral Ohm's law, first, the results from two prosed methods were compared to those from Sato's approach and an analytic solution in parallel plane electrodes. After verification, the generalized method was applied to the tip-sphere electrodes for evaluating the terminal current with three carriers and the Fowler-Nordheim field emission condition. From these results, we concluded that the generalized energy method can be a consistent technique for evaluating the discharge current with various dielectric materials or large magnetic field.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1698-1704
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• 2012

Resveratrol, or its glycoside form piceid, is a dietary antioxidant polyphenolic compound, found in grapes and red wine that has been shown to have protective effects against cardiovascular disease. However, very low water solubility of the compound may limit its application in the food and pharmaceutical industries. The amylosucrase (AMAS) of Alteromonas macleodii Deep ecotype was expressed in Escherichia coli and showed high glycosyltransferase activity to produce the glucosyl piceid when piceid was used as an acceptor. The conversion yield of piceid glucoside was 35.2%. Biotransformation using culture of the E. coli harboring the amas gene increased the yield up to 70.8%. The transfer product was purified by reverse phase chromatography and recycling preparative HPLC, and the molecular structure of the piceid glucoside was determined using NMR spectroscopy. The piceid glucoside was identified as glucosyl-${\alpha}$-($1{\rightarrow}4$)-piceid. The solubility of glucosyl piceid was 5.26 and 1.14 times higher than those of resveratrol and piceid, respectively. It is anticipated that dietary intake of this compound is more effective by enhancing the bioavailability of resveratrol in the human body because of its hydrophilic properties in the intestinal fluid.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.3
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• pp.1-1
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• 1987

The accurate prediction of the ship wave resistance is very important to design ships which operate satisfactorily in a wave environment. Thus, work should continue on development and validation of methods to compute ship wave patterns and wave resistance. Research efforts to improve the prediction of ship waves and wavemaking resistance are categorized in two major areas. First is the development of higher-order theories to take account of the nonlinear effect of the free surface condition and improved analytical treatment of the body boundary condition. Second is the development of direct numerical methods aimed at solving body and free-surface boundary conditions as accurately as possible. A new formulation of the slender body theory for a ship with constant speed is developed by Maruo. It is quite different from the existing slender ship theory by Vossers, Maruo and Tuck. It may be regarded as a substitute for the Neumann-Kelvin approximation. In present work, the method of asymptotic expansion of the Kelvin source is applied to obtain a new wave resistance formulation in fluid of finite depth. It takes a simple form than existing theory.

• Wind and Structures
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• v.29 no.5
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• pp.339-359
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• 2019

Pre-stressed concrete poles are among the supporting systems used to support transmission lines. It is essential to protect transmission line systems from harsh environmental attacks such as downburst wind events. Typically, these poles are designed to resist synoptic wind loading as current codes do not address high wind events in the form of downbursts. In the current study, the behavior of guyed pre-stressed concrete Transmission lines is studied under downburst loads. To the best of the authors' knowledge, this study is the first investigation to assess the behaviour of guyed pre-stressed concrete poles under downburst events. Due to the localized nature of those events, identifying the critical locations and parameters leading to peak forces on the poles is a challenging task. To overcome this challenge, an in-house built numerical model is developed incorporating the following: (1) a three-dimensional downburst wind field previously developed and validated using computational fluid dynamics simulations; (2) a computationally efficient analytical technique previously developed and validated to predict the non-linear behaviour of the conductors including the effects of the pretension force, sagging, insulator's stiffness and the non-uniform distribution of wind loads, and (3) a non-linear finite element model utilized to simulate the structural behaviour of the guyed pre-stressed concrete pole considering material nonlinearity. A parametric study is conducted by varying the downbursts locations relative to the guyed pole while considering three different span values. The results of this parametric study are utilized to identify critical downburst configurations leading to peak straining actions on the pole and the guys. This is followed by comparing the obtained critical load cases to new load cases proposed to ASCE-74 loading committee. A non-linear failure analysis is then conducted for the three considered guyed pre-stressed concrete transmission line systems to determine the downburst jet velocity at which the pole systems fail.

• Steel and Composite Structures
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• v.10 no.2
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• pp.129-149
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• 2010

The objective of this study is to formulate a general 3D material-structural analysis framework for the thermomechanical behavior of steel-concrete structures in a fire environment. The proposed analysis framework consists of three sequential modeling parts: fire dynamics simulation, heat transfer analysis, and a thermomechanical stress analysis of the structure. The first modeling part consists of applying the NIST (National Institute of Standards and Technology) Fire Dynamics Simulator (FDS) where coupled CFD (Computational Fluid Dynamics) with thermodynamics are combined to realistically model the fire progression within the steel-concrete structure. The goal is to generate the spatial-temporal (ST) solution variables (temperature, heat flux) on the surfaces of the structure. The FDS-ST solutions are generated in a discrete form. Continuous FDS-ST approximations are then developed to represent the temperature or heat-flux at any given time or point within the structure. An extensive numerical study is carried out to examine the best ST approximation functions that strike a balance between accuracy and simplicity. The second modeling part consists of a finite-element (FE) transient heat analysis of the structure using the continuous FDS-ST surface variables as prescribed thermal boundary conditions. The third modeling part is a thermomechanical FE structural analysis using both nonlinear material and geometry. The temperature history from the second modeling part is used at all nodal points. The ABAQUS (2003) FE code is used with external user subroutines for the second and third simulation parts in order to describe the specific heat temperature nonlinear dependency that drastically affects the transient thermal solution especially for concrete materials. User subroutines are also developed to apply the continuous FDS-ST surface nodal boundary conditions in the transient heat FE analysis. The proposed modeling framework is applied to predict the temperature and deflection of the well-documented third Cardington fire test.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.17-23
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• 2020

In this paper, the efficient periodic unsteady flow analysis is developed by using a Chebyshev collocation operator applied to the time differential term of the governing equations. The partial implicit time integration method was also applied in the governing equation for a fluid, which means flux terms were implicitly processed for a time integration and the time derivative terms were applied explicitly in the form of the source term by applying the Chebyshev collocation operator. To verify this method, we applied the 1D unsteady Burgers equation and the 2D oscillating airfoil. The results were compared with the existing unsteady flow frequency analysis technique, the Harmonic Balance Method, and the experimental data. The Chebyshev collocation operator can manage time derivatives for periodic and non-periodic problems, so it can be applied to non-periodic problems later.

• Neonatal Medicine
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• v.28 no.3
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• pp.133-138
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• 2021

Osteopetrosis refers to a group of genetic skeletal disorders characterized by osteosclerosis and fragile bones. Osteopetrosis can be classified into autosomal dominant, autosomal recessive, or X-linked forms, which might differ in clinical characteristics and disease severity. Autosomal recessive osteopetrosis, also known as malignant osteopetrosis, has an earlier onset, more serious clinical symptoms, and is usually fatal. We encountered a 1-day-old girl who was born full-term via vaginal delivery, which was complicated by meconium-stained amniotic fluid, cephalo-pelvic disproportion, and nuchal cord. Routine neonatal care was provided, in addition to blood tests and chest radiography to screen for sepsis, as well as skull radiography to rule out head injuries. Initial blood tests revealed hypocalcemia, which persisted on follow-up tests the next day. Radiographic examinations revealed diffusely increased bone density and a "space alien" appearance of the skull. Based on radiographic and laboratory findings, the infantile form of osteopetrosis was suspected and genetic testing for identification of the responsible gene. Eventually, a heterozygous mutation of the T cell immune regulator 1, ATPase H+ transporting V0 subunit a3 (TCIRG1) gene (c.292C>T) was identified, making this the first reported case of neonatal-onset malignant osteopetrosis with TCIRG1 mutation in South Korea. Early-onset hypocalcemia is common and usually results from prematurity, fetal growth restriction, maternal diabetes, perinatal asphyxia, and physiologic hypoparathyroidism. However, if hypocalcemia persists, we recommend considering 'infantile of osteopetrosis' as a rare cause of neonatal hypocalcemia and performing radiographic examinations to establish the diagnosis.

• Journal of Gastric Cancer
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• v.19 no.1
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• pp.72-82
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• 2019

Purpose: Despite its clinical benefits, enhanced recovery after surgery (ERAS) is less widely implemented for gastric cancer surgery. This nationwide survey investigated the current status of the implementation of ERAS in perioperative care for gastric cancer surgery in South Korea. Materials and Methods: This survey enrolled 89 gastric surgeons from 52 institutions in South Korea. The questionnaire consisted of 24 questions about the implementation of the ERAS protocols in the management of gastric cancer surgery. The survey was carried out using an electronic form sent via email. Results: Of the 89 gastric surgeons, 58 (65.2%) answered that they have knowledge of the concept and details of ERAS, 45 (50.6%) of whom were currently applying ERAS for their patients. Of the ERAS protocols, preoperative education (91.0%), avoidance of preoperative fasting (68.5%), maintenance of intraoperative normothermia (79.8%), thromboprophylaxis (96.5%), early active ambulation (64.4%), and early removal of urinary catheter (68.5%) were relatively well adopted in perioperative care. However, other practices, such as avoidance of preoperative bowel preparation (41.6%), provision of preoperative carbohydrate-rich drink (10.1%), avoidance of routine abdominal drainage (31.4%), epidural anesthesia (15.9%), single-dose prophylactic antibiotics (19.3%), postoperative high oxygen therapy (36.8%), early postoperative diet (14.6%), restricted intravenous fluid administration (53.9%), and application of discharge criteria (57.3%) were not very well adopted for patients. Conclusions: Perioperative management of gastric cancer surgery is largely heterogeneous among gastric surgeons in South Korea. Standard perioperative care based on scientific evidence needs to be established to improve the quality of surgical care and patient outcomes.

• Journal of Korean Medical classics
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• v.34 no.4
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• pp.27-64
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• 2021

Objectives : This paper examined the Buddhist contents within the text, Bencaoshengyabanji(本草乘雅半偈). Methods : Medicinals that were searched through Buddhist vocabulary were examined. Results & Conclusions : Medicinals that quoted the Lengyanjing were related to the Water-Fire interaction, food and medicine, and karma, while those that quoted the Shidian were related to 無上道, 去惡殺蟲, 樞機滑利, and 生生之氣. Those related to the Great Earth of the Four Elements corrected the body's form based on Metal Qi, while those related to the Great Water were connected to the circulation of water dampness. Those related to the Great Fire were deeply related to Yang Qi, and those related to the Great Wind were connected to Wind control. Of the Four Origins, medicinals that were viviparous lowered Qi, while those that were oviparous were related to communicating Shen, treating diseases of the Conception Vessel, and the closing and opening of day and night. Medicinals originating from dampness were related to urination and fluid management, while those of metamorphosis were related to the process of Qi. Those related to emptiness were related to the communication of the Qi system, while those related to 六根六塵 were connected to calming the Shen and strengthening the will, and smoothing the nine orifices. Medicinals related to 圓通 were used for improving eyesight and hearing and controlling the closing and opening. Lu Zhi-yi's analysis of medicinals through the Lengyanjing is original in that it suggested a new perspective other than previous theories on pharmacology which were based on the Yin-Yang and Five Phases and Rising/Lowering/Floating/Sinking theories, but also pedantic and exaggerated. The Bencaoshengyabanji is a unique text on medicinals which analyzed each medicinal under Buddhist influence. However, it also followed the contexts of other previous texts on medicinals, and influenced Zou shu.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.120-130
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• 2021

The spinal cord or CSF surgery is a very complex process. It requires continuous pre and post-surgery evaluation to have a better ability to diagnose the disease. To detect automatically the suspected areas of tumors and symptoms of CSF leakage during the development of the tumor inside of the brain. We propose a new method based on using computer software that generates statistical results through data gathered during surgeries and operations. We performed statistical computation and data collection through the Google Source for the UK National Cancer Database. The purpose of this study is to address the above problems related to the accuracy of missing hybrid KNN values and finding the distance of tumor in terms of brain cancer or CSF images. This research aims to create a framework that can classify the damaged area of cancer or tumors using high-dimensional image segmentation and Laplace transformation method. A high-dimensional image segmentation method is implemented by software modelling techniques with measures the width, percentage, and size of cells within the brain, as well as enhance the efficiency of the hybrid KNN algorithm and Laplace transformation make it deal the non-zero values in terms of missing values form with the using of Frobenius Matrix for deal the space into non-zero values. Our proposed algorithm takes the longest values of KNN (K = 1-100), which is successfully demonstrated in a 4-dimensional modulation method that monitors the lighting field that can be used in the field of light emission. Conclusion: This approach dramatically improves the efficiency of hybrid KNN method and the detection of tumor region using 4-D segmentation method. The simulation results verified the performance of the proposed method is improved by 92% sensitivity of 60% specificity and 70.50% accuracy respectively.