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Parallel Iterative FEM Solver with Initial Guess for Frequency Domain Electromagnetic Analysis

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Intelligent Automation & Soft Computing 2023年第5期36卷 1585-1602页

作者： Woochan Lee Woobin park Jaeyoung park Young-joon Kim Moonseong Kim Department of Electrical Engineering Incheon National UniversityIncheon22012Korea Department of Computer Engineering Hongik UniversitySeoul04066Korea Department of Electronic Engineering Gachon UniversitySeongnam13120Korea Department of IT Convergence Software Seoul Theological UniversityBucheon14754Korea

The finite element method is a key player in computational electromag-netics for designing RF(Radio Frequency)components such as *** frequency-domain analysis is fundamental to identify the characteristics of the *** the conventional frequency-domain electromagnetic analysis using FEM(Finite Element Method),the system matrix is complex-numbered as well as indeﬁ*** iterative solvers can be faster than the direct solver when the solver convergence is guaranteed and done in a few ***,such complex-numbered and indeﬁnite systems are hard to exploit the merit of the iterative *** is also hard to beneﬁt from matrix factorization techniques due to varying system matrix parts according to ***,it is hard to adopt conventional iterative solvers even though the system matrix is sparse.A new parallel iterative FEM solver for frequency domain analysis is implemented for inhomogeneous waveguide structures in this *** this implementation,the previous solution of the iterative solver of Matlab(Matrix Laboratory)employ-ing the preconditioner is used for the initial guess for the next step’s solution *** overlapped parallel stage using Matlab’s Parallel Computing Toolbox is also proposed to alleviate the cold starting,which ruins the convergence of early steps in each parallel *** experiments based on waveguide structures have demonstrated the accuracy and efﬁciency of the proposed scheme.

关键词： Computational electromagnetics numerical simulation ﬁnite element method parallel processing iterative solvers

Gardenia jasminoides protects against cerulein-induced acute pancreatitis

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World Journal of Gastroenterology 2008年第40期14卷 6188-6194页

作者： Won-seok Jung Young-seok Chae Do-Yun Kim Sang-Wan Seo Hee-Je park Gi-Sang Bae Tae-Hyeon Kim Hyo-Jeong Oh Ki-Jung Yun Rae-Kil park Jong-Suk Kim Eun-Cheol Kim Sung-Yeon Hwang Sung-Joo park Ho-joon Song Department of Biochemistry Institute of Medical ScienceChonbuk National University Medical School Department of Herbology School of Oriental MedicineWonkwang University Kohwang Medical Institute College of MedicineKyung Hee University Department of internal medicine College of MedicineWonkwng University Department of Pathology College of MedicineWonkwng University Vestibulocochlear Research Center & Department of Microbiology College of MedicineWonkwng University Department of Oral & Maxillofacial Pathology Dental CollegeWonkwang University

AIM： To investigate the effect of Garden/a fasm/noides （GJ） on cerulein-induced acute pancreatitis （AP） in mice. METHODS： C57BL/6 mice weighing 18-20 g were divided into three groups. （1） Normal salinetreated group, （2） treatment with GJ at a dose of 0.1 g/kg, （3） treatment with GJ at a dose of 1 g/kg. GJ was administered orally （n = 6 per group） for 1 wk. Three hours later, the mice were given anintraperitoneal injection of cerulein （50 μg/kg）, a stable cholecystokinin （CCK） analogue, every hour for a total of 6h as described previously. The mice were sacrificed at 6 h after completion of cerulein injections. Blood samples were obtained to determine serum amylase, lipase and cytokine levels. The pancreas was rapidly removed for morphologic examination and scoring. A portion of pancreas was stored at -70℃ and prepared for the measurement of tissue myeloperoxidase （MPO） activity, an indicator of neutrophil sequestration, and for reverse-transcriptase PCR （RT-PCR） and real-time PCR measurements. RESULTS： Treatment with G.1 decreased significantly the severity of pancreatitis and pancreatitis-associated lung injury. Treatment with G.1 attenuated the severity of AP compared with saline-treated mice, as shown by reduction in pancreatic edema, neutrophil infiltration, serum amylase and lipase levels, serum cytokine levels, and mRNA expression of multiple inflammatory mediators. CONCLUSION： These results suggest that GJ attenuated the severity of AP as well as pancreatitisassociated lung injury.

关键词： Gardenia Jasminoides Acute pancreatitis Cerulein

Evaluation of esophageal function in patients with esophageal motor abnormalities using multichannel intraluminal impedance esophageal manometry

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World Journal of Gastroenterology 2006年第39期12卷 6349-6354页

作者： Yu Kyung Cho Myung-Gyu Choi Jae Myung park Jung Hwan Oh Chang Nyol Paik joon Wook Lee In seok Lee Sang Woo Kim In-Sik Chung Division of Gastroenterology Department of Internal Medicine The Catholic University of Korea Seoul Korea

AIM: To evaluate the functional aspect of esophageal motility in healthy subjects and in patients who were referred for esophageal function testing using multichannel intraluminal impedance-esophageal manometry (MII-EM), and to assess the clinical utility of MII-EM. METHODS: From September 2003 to January 2004, we performed the MII-EM on healthy volunteers and all the patients who were referred for esophageal function testing. Each patient received 10 liquid and 10 viscous swallows. We analyzed the results, the impedance and the manometric findings. Some of the subjects had additional ambulatory 24-h pH study performed to diagnose gastroesophageal reflux disease (GERD). RESULTS: Among 89 studied subjects, the MII-EM findings showed normal esophageal motility in 50 (56.17%), ineffective esophageal motility (IEM) in 17 (19.10%), nutcracker esophagus in 7 (7.86%), achalasia in 4 (4.49%), and scleroderma esophagus in 11 (12.35%) cases. The completeness and the speed of bolus transit were in the order of nutcracker esophagus, normal manometry and IEM. Some of the swallows showing normal manometry and IEM had incomplete transit. In the achalasia and scleroderma esophagus, almost all the swallows had incomplete transit. The body amplitudes were higher for the swallows with complete transit than for the swallows with incomplete transit. There was not a significant difference in the manometric and impedance findings between the subjects with and without GERD. CONCLUSION: MII-EM is a useful tool in assessing theesophageal function in the patients having esophageal motility abnormality. The primary factors influencing the bolus transit are the amplitude of the esophageal body and normal peristalsis.

关键词： Impedance manometry Esophageal function Motility Bolus transit

Precise control of surface oxygen vacancies in ZnO nanoparticles for extremely high acetone sensing response

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Journal of Advanced Ceramics 2022年第5期11卷 769-783页

作者： Jihyun LEE Youngmoon CHOI Byoung joon park Jeong Woo HAN Hyun-Sook LEE Jong Hyeok park Wooyoung LEE Department of Materials Science and Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Chemical and Biological Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Chemical Engineering Pohang University of Science and TechnologyPohang 37673Republic of Korea Institute for Convergence Research and Education in Advanced Technology Yonsei UniversitySeoul 03722Republic of Korea

ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast ***,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders.A combination of H_(2)O_(2)treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles(NPs).The highest response of~27,562 was achieved for 10 ppm acetone in 0.125 MH_(2)O_(2)treated/annealed ZnO NPs at the optimal working temperature of 400℃,which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors(MOSs).Furthermore,first-principles calculations indicate that pre-adsorbed O formed on the surface of H_(2)O_(2)treated ZnO NPs can provide favorable adsorption energy,especially for acetone detection,due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO *** study demonstrates that controlling surface oxygen vacancies by H_(2)O_(2)treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.

关键词： gas sensors acetone metal oxide semiconductors(MOSs) ZnO nanoparticles(NPs) H_(2)O_(2)treatment

Hematologic diseases: High risk of Clostridium difficile associated diarrhea

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World Journal of Gastroenterology 2014年第21期20卷 6602-6607页

作者： Tae-Geun Gweon Myung-Gyu Choi Myong Ki Baeg Chul-Hyun Lim Jae Myung park In seok Lee Sang Woo Kim Dong-Gun Lee Yeon joon park Jong Wook Lee Division of Gastroenterology Department of Internal MedicineSeoul St Mary’s hospitalThe Catholic University of KoreaCollege of MedicineSeoul 137-701South Korea Division of Infectious Diseases Department of Internal MedicineSeoul St Mary’s hospitalThe Catholic University of KoreaCollege of MedicineSeoul 137-701South Korea Department of Laboratory Medicine Seoul St Mary’s hospitalThe Catholic University of KoreaCollege of MedicineSeoul 137-701South Korea Division of Hematologic Diseases Department of Internal MedicineSeoul St Mary’s hospitalThe Catholic University of KoreaCollege of MedicineSeoul 137-701South Korea

AIM: To investigate the incidence and clinical outcome of Clostridium difficile (C. difficile) associated diarrhea (CDAD) in patients with hematologic disease.

关键词： Clostridium difficile associated diarrhea Incidence Clinical outcome Patients with hematologic disease Intravenous immunoglobulin

Calcium-dependent proteasome activation is required for axonal neurofilament degradation

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Neural Regeneration Research 2013年第36期8卷 3401-3409页

作者： Joo Youn park So Young Jang Yoon Kyung Shin Duk joon Suh Hwan Tae park Department of Physiology Mitochondria Hub Regulation Center College of Medicine Dong-A University

Even though many studies have identified roles of proteasomes in axonal degeneration, the mo- lecular mechanisms by which axonal injury regulates proteasome activity are still unclear. In the present study, we found evidence indicating that extracellular calcium influx is an upstream regulator of proteasome activity during axonal degeneration in injured peripheral nerves. In degenerating axons, the increase in proteasome activity and the degradation of ubiquitinated proteins were sig- nificantly suppressed by extracellular calcium chelation. In addition, electron microscopic findings revealed selective inhibition of neurofilament degradation, but not microtubule depolymerization or mitochondrial swelling, by the inhibition of calpain and proteasomes. Taken together, our findings suggest that calcium increase and subsequent proteasome activation are an essential initiator of neurofilament degradation in Wallerian degeneration.

关键词： neural regeneration peripheral nerve injury neurofilament degradation sciatic nerve calcium calpain mitochondria microtubule depolymerization axon axon degeneration neuroregeneration

Unilateral foveomacular retinitis resembling solar retinopathy among young soldiers in Korean army and associated multimodal imaging findings

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International Journal of Ophthalmology(English edition) 2020年第1期13卷 112-119页

作者： Chang Ki Yoon Kyu Hyung park Se joon Woo Department of Ophthalmology Seoul National University College of MedicineSeoul National University Bundang HospitalSeongnam 13620Korea Department of Ophthalmology Hallym University College of MedicineHallym University Kangnam Sacred Heart HospitalSeoul 07441Korea

AIM: To describe the clinical features and multimodal images of unilateral foveomacular retinitis in young Korean soldiers. METHODS: Ten patients having foveomacular retinitis were included. Fluorescein angiography, fundus autofluorescence(FAF), infrared reflectance(IR), and spectral-domain optical coherence tomography(SD-OCT) were ***: All patients were young males experienced insidious visual decline without exposure to bright light. Initial and final vision ranged from hand movement to 20/20(median 20/200) and 20/2000 to 20/20(median 20/500), respectively. Vision decreased in 6 patients while improved in two. Typical macular abnormality was yellow granular spots. SD-OCT showed ellipsoid zone(EZ) or interdigitation zone(IZ) disruption of fovea. The degree of EZ/IZ damage correlated with vision. Lesions were clearly visualized through IR and matched with SD-OCT ***: This is the first case series of foveomacular retinitis diagnosed with multimodal imaging. Foveomacular retinitis should be suspected in sudden unilateral visual decline especially in young soldiers. SD-OCT is the most important diagnostic modality.

关键词： foveomacular retinitis Korean multimodal imaging solar retinopathy soldiers unilateral

Electrophoretic Deposition of Oxide Nanoparticles for Electron Emission Enhancement

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Journal of Materials Science & Technology 2010年第11期26卷 1032-1036页

作者： Jong Rok Ahn Gil Seon Kang Hwack Joo Lee Chang joon park Korea Research Institute of standards and Science

Four oxide nanoparticles,such as yttrium oxide,lanthanum oxide,cerium oxide and zirconium oxide were coated on rhenium filaments by an electrophoretic deposition *** oxide coatings were examined by scanning electron microscopy,and electron emission characteristics of the oxide-coated rhenium were studied to find alternative oxide materials for replacing the hazardous thorium *** four oxides tested in this work,yttrium oxide and lanthanum oxide coated rhenium showed enhanced electron emission compared with an uncoated ***,lanthanum oxide coating evaporated too quickly in a vacuum chamber,and hence yttrium oxide was found to be the only alternative material for use in a routine mass *** optimum coating thickness of the yttrium oxide and lanthanum oxide was around 20 μm.

关键词： Electrophoretic deposition Oxide nanoparticles Scanning electron microscopy (SEM) Electron emission

Mimicking a Superhydrophobic Insect Wing by Argon and Oxygen Ion Beam Treatment on Polytetrafluoroethylene Film

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Journal of Bionic Engineering 2009年第4期6卷 365-370页

作者： Youngjong Lee Yonghoon Yoo Jihoon Kim Sriyulianti Widhiarini Baeho park Hoon Cheol park Kwang joon Yoon Doyoung Byun Department of Aerospace Information Engineering Konkuk UniversitySeoul 143-701Republic of Korea Department of Physics Konkuk UniversitySeoul 143-701Republic of Korea Department of Advanced Technology Fusion Konkuk UniversitySeoul 143-701Republic of Korea

Biological tiny structures have been observed on many kinds of surfaces such as lotus leaves and insect wings,which enhance the hydrophobicity of the natural surfaces and play a role of *** presented the fabrication technology of a superhydrophobic surface using high energy ion *** insect wings that mimic the morphology and the superhydrophobocity of cicada's wings were successfully fabricated using argon and oxygen ion beam treatment on a polytetrafluoroethylene (PTFE)*** wing structures were supported by carbon/epoxy fibers as artificial flexible veins that were bonded through an autoclave *** morphology of the fabricated surface bears a strong resemblance to the wing surface of a cicada,with contact angles greater than 160°,which could be sustained for more than two months.

关键词： superhydrophobic insect wing mimicry of the wing ion beam treatment artificial flapper dynamic contact angle