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Weighted Gauss-Seidel Precoder for Downlink Massive MIMO Systems

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Computers, Materials & Continua 2021年第5期67卷 1729-1745页

作者： Jun-Yong jang Won-Seok Lee jae-Hyun Ro Young-Hawn You Hyoung-Kyu Song Department of Information and Communication Engineering Convergence Engineering for Intelligent DroneSejong UniversitySeoul05006Korea Department of Computer Engineering Sejong UniversitySeoul05006Korea

In this paper,a novel precoding scheme based on the Gauss-Seidel(GS)method is proposed for downlink massive multiple-input multiple-output(MIMO)*** GS method iteratively approximates the matrix inversion and reduces the overall complexity of the precoding *** addition,the GS method shows a fast convergence rate to the Zero-forcing(ZF)method that requires an exact invertible ***,to satisfy demanded error performance and converge to the error performance of the ZF method in the practical condition such as spatially correlated channels,more iterations are necessary for the GS method and increase the overall *** efficient approximation with fewer iterations,this paper proposes a weighted GS(WGS)method to improve the approximation accuracy of the GS *** optimal weights that accelerate the convergence rate by improved accuracy are computed by the least square(LS)*** the computation of weights,the different weights are applied for each iteration of the GS *** addition,an efficient method of weight computation is proposed to reduce the complexity of the LS *** simulation results show that bit error rate(BER)performance for the proposed scheme with fewer iterations is better than the GS method in spatially correlated channels.

关键词： Massive MIMO GS matrix inversion complexity weight

High-damping and conducting epoxy nanocomposite using both zinc oxide particles and carbon nanofibers

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Journal of Materiomics 2018年第3期4卷 187-193页

作者： jae-Soon jang Gyo Woo Lee Hyung-ick Kim Sung Yong Hong Lijie Ci jae-Do Nam Jonghwan Suhr Simulation Group Battery R&D CenterSAMSUNG SDI CO.LTDSamsung-RoYeongtong-GuSuwon-SiGyeonggi-DoSouth Korea Division of Mechanical Design Engineering Chonbuk National UniversityJeonju561-756South Korea Dongnam Regional Division Korea Institute of Industrial TechnologyJinju 52845South Korea Department of Polymer Science and Engineering Sungkyunkwan University2066SeoburoJangan-guGyeonggi-doSouth Korea School of Materials Science&Engineering Shandong UniversityChina School of Mechanical Engineering Sungkyunkwan University2066SeoburoJangan-guGyeonggi-doSouth Korea Department of Energy Science Sungkyunkwan University2066SeoburoJangan-guGyeonggi-doSouth Korea

In this study,high-damping and conducting epoxy nanocomposites were developed with carbon nanofibers as conducting materials,and zinc oxide particles as piezoelectric *** mechanical and electrical properties,electrical impedance,and loss factors were investigated by uniaxial tensile tests,voltage measurement,impedance measurement,and 3-point bending *** percolation thresholds were found:the percolation threshold of resistivity due to the carbon nanofibers forming conductive networks in the matrix;and the impedance threshold due to the zinc oxide particles acting like electric barriers.A poling treatment of the high-damping and conducting epoxy nanocomposite was considered,and we found that poling treatment helped to make the networks more conductive and to generate voltage from ZnO particles.A high-damping and conducting epoxy nanocomposite with 3 wt%CNF and 10 wt%ZnO exhibited higher loss factor than those of others tested.

关键词： Damping Piezoelectric materials Impedance Poling treatment Loss factor

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World Journal of Clinical Cases 2020年第21期8卷 5341-5346页

作者： eun-A jang Tae-Young Kim Eu-Gene Jung Seongtae Jeong Hong-Beom Bae Seongheon Lee Department of Anesthesiology and Pain Medicine Chonnam National University Medical SchoolChonnam National University HospitalGwangju 61469South Korea

BACKGROUND Donepezil is an acetylcholinesterase inhibitor used to improve cognition and delay disease progression in dementia patients by increasing acetylcholine *** drug may potentially interact with neuromuscular blocking agents(NMBAs)that act on muscular acetylcholine receptors during general ***,we present a case of inadequate neuromuscular blockade with rocuronium,a nondepolarizing NMBA,in a dementia patient who had taken *** SUMMARY A 71-year-old man was scheduled for laparoscopic *** had been taking donepezil 5 mg for *** anesthesia was induced with propofol and *** depth of neuromuscular blockade was monitored by train-of-four(TOF)*** the administration of rocuronium,the TOF ratio decreased at an unusually slow rate,and a TOF count of 0 was detected 7 min *** intubation,a TOF count of 1 was detected within 1 min,and a TOF ratio of 12%was detected within 2 *** TOF count remained at 4 even with an additional bolus and continuous infusion of rocuronium,suggesting resistance to this *** of propofol,an inhalation anesthetic was administered alongside another NMBA(cisatracurium).Then,the quality of neuromuscular blockade improved,and the TOF count remained at 0-1 for the next 70 *** further problems were encountered with respect to surgery or *** Donepezil may be responsible for inadequate neuromuscular blockade during anesthesia,especially when total intravenous anesthesia is used.

关键词： Donepezil Dementia General anesthesia Rocuronium Neuromuscular blocking agents Case report

Outcome after endoscopic submucosal dissection for early gastric cancer in Korea

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World Journal of Gastroenterology 2011年第31期17卷 3591-3595页

作者： Jun Haeng Lee Su Jin Hong jae Young jang Seong eun Kim Sang Young Seol Department of Medicine Samsung Medical CenterSungkyunkwan University School of Medicine Department of Internal Medicine Digestive Disease CenterInstitute for Digestive ResearchSoon Chun Hyang University College of Medicine Department of Internal Medicine Kyung Hee University College of Medicine Department of Internal Medicine Ewha Womans University School of MedicineEwha Medical Research Institute Division of Gastroenterology and Hepatology Department of Internal MedicineInje University College of Medicine

Endoscopic treatment,such as endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD),has been established as one of the treatment options for selected cases with early gastric cancer(EGC).Most studies on this topic have been carried out by researchers in ***,the experience in EMR/ESD for EGC outside Japan is increasingly *** Korea,gastric cancer is the most common malignant disease,and the second leading cause of cancer ***,EMR for EGC is widely performed in many centers in *** results with a shortterm follow-up period are very promising in *** resection rate of EMR was 37.8%-94.3%,and that of ESD was 77.4%-93.1%.In this review,we will provide an overview of the outcomes of endoscopic treatments in Korea.

关键词： Early gastric cancer Endoscopic mucosal resection Endoscopic submucosal dissection Outcome

Characterization of smooth muscle, enteric nerve, interstitial cells of Cajal, and fibroblast-like cells in the gastric musculature of patients with diabetes mellitus

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World Journal of Gastroenterology 2016年第46期22卷 10131-10139页

作者： Kyung Sik Park Kwang Bum Cho Il Seon Hwang jae Hyung Park Byung Ik jang Kyeong Ok Kim Sung Woo Jeon eun Soo Kim Chang Sik Park Joong Goo Kwon Department of Internal Medicine Keimyung University School of Medicine Department of Pathology Keimyung University School of Medicine Department of Physiology Keimyung University School of Medicine Department of Internal Medicine Youngnam University College of Medicine Department of Internal Medicine Kyungpook National University School of Medicine Department of Advanced Materials Convergence Korea Institute of Ceramic Engineering and Technology Department of Internal Medicine Catholic University of Daegu School of Medicine

AIM To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus(DM).METHODS Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cancer. H&E stain and Masson's Trichrome stain were performed to assess the degree of fibrosis. Immunohistochemical staining using various antibodies was also performed [antibodies against protein gene product 9.5(PGP9.5), neuronal nitric oxide synthase(n NOS), vasoactive intestinal peptide(VIP), neurokinin-1(NK1) receptor, c-Kit, and platelet-derived growth factor receptor-alpha,(PDGFRα)]. Immunofluorescent staining and evaluation with confocal microscopy were also *** Twenty-six controls and 35 diabetic patients(21 shortduration patients and 14 long-duration patients) were included. There were no significant differences in basic demographics between the two groups except in mean body mass index(BMI)(higher in the DM group). Proportions of moderate-to-severe intercellular fibrosis in the muscle layer were significantly higher in the DM group than in the control group(P < 0.01). On immunohistochemical staining, c-Kit- and PDGFRα-positive immunoreactivity were significantly decreased in the DM group compared with the control group(P < 0.05). There were no statistically significant differences in PGP9.5, n NOS, VIP, and neurokinin 1 expression. On immunofluorescent staining, cellularity of interstitial cells of Cajal(ICC) was observed to decrease with increasing duration of *** Our study suggests that increased intercellular fibrosis, loss of ICC, and loss of fibroblast-like cells are found in the smooth muscle of DM patients. These abnormalities may contribute to changes in gastric motor activity in patients with DM.

关键词： Diabetes mellitus Interstitial cells of Cajal Fibroblast-like cell Gastroparesis Enteric nerve system

Dragging 3D printing technique controls pore sizes of tissue engineered blood vessels to induce spontaneous cellular assembly

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Bioactive Materials 2024年第1期31卷 590-602页

作者： Hun-Jin Jeong Hyoryung Nam jae-Seok Kim Sungkeon Cho Hyun-Ha Park Young-Sam Cho Hyungkook Jeon Jinah jang Seung-jae Lee Department of Mechanical Engineering Wonkwang University54538IksanRepublic of Korea Department of Convergence IT Engineering Pohang University of Science and Technology37673PohangGyeongbukRepublic of Korea Department of Mechanical and Design Engineering Wonkwang University54538IksanRepublic of Korea Department of Mechanical Engineering Pohang University of Science and Technology37673PohangGyeongbukRepublic of Korea School of Interdisciplinary Bioscience and Bioengineering Pohang University of Science and Technology37673PohangGyeongbukRepublic of Korea Institute of Convergence Science Yonsei University03722SeoulRepublic of Korea Regenerative Engineering Laboratory Columbia University630W 168th STNew York10032USA Department of Manufacturing Systems and Design Engineering Seoul National University of Science and Technology01811SeoulRepublic of Korea

To date,several off-the-shelf products such as artificial blood vessel grafts have been reported and clinically tested for small diameter vessel(SDV)***,conventional artificial blood vessel grafts lack endothelium and,thus,are not ideal for SDV transplantation as they can cause *** addition,a suc-cessful artificial blood vessel graft for SDV must have sufficient mechanical properties to withstand various external ***,we developed a spontaneous cellular assembly SDV(S-SDV)that develops without additional *** improving the dragging 3D printing technique,SDV constructs with free-form,multilayers and controllable pore size can be fabricated at ***,The S-SDV filled in the natural poly-mer bioink containing human umbilical vein endothelial cells(HUVECs)and human aorta smooth muscle cells(HAoSMCs).The endothelium can be induced by migration and self-assembly of endothelial cells through pores of the SDV *** antiplatelet adhesion of the formed endothelium on the luminal surface was also *** addition,this S-SDV had sufficient mechanical properties(burst pressure,suture retention,leakage test)for *** believe that the S-SDV could address the challenges of conventional SDVs:notably,endothelial formation and mechanical *** particular,the S-SDV can be designed simply as a free-form structure with a desired pore *** endothelial formation through the pore is easy even in free-form con-structs,it is expected to be useful for endothelial formation in vascular structures with branch or curve shapes,and in other tubular tissues such as the esophagus.

关键词： Small diameter vessel Dragging 3D printing Pore control Spontaneous cellular assembly

Colonic lipoma covered by hyperplastic epithelium: Case report

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World Journal of Clinical Cases 2013年第3期1卷 124-127页

作者： Ju-Ok Yeom Sun-Young Kim eun-Chul jang Ji-Youn Yu eun Deok Chang Young-Seok Cho Division of Gastroenterology Department of Internal MedicineUijeongbu St. Mary’s Hospitalthe Catholic University of Korea College of MedicineUijeongbu 480-717South Korea Departement of Cilinical Pathology Uijeong-bu St. Mary’s Hospitalthe Catholic University of Korea College of MedicineUijeongbu 480-717South Korea

Colonic lipomas are submucosal nonepithelial tumors covered by intact or eroded mucosa. In rare cases, alterations in the mucosa covering a lipoma include hyperplasia, adenoma, atrophy, ulceration, and necrosis. Here, we report a case of a colonic lipoma covered by hyperplastic epithelium in a 68-year-old woman. Based on the colonoscopy findings, a snare polypectomy was performed for a presumptive diagnosis of an epithelial lesion; however, the histological examination revealed a colonic submucosal lipoma with overlying hyperplastic epithelium.

关键词： Lipoma Colonic lipomas Hyperplastic Colonoscopy

A feasible route to produce 1.1 GPa ferritic-based low-Mn lightweight steels with ductility of 47%

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Journal of Materials Science & Technology 2022年第22期117卷 225-237页

作者： Kwang Kyu Ko Hyo Ju Bae eun Hye Park Hyeon-Uk Jeong Hyoung Seok Park jae Seok Jeong Jung Gi Kim Hyokyung Sung Nokeun Park jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering Yeungnam UniversityGyeongbuk 38541South Korea Materials Research Team R&D Hyundai MobisYongin 16891South Korea Materials Technology Development Team Doosan Heavy Industries&ConstructionChangwon 51711South Korea

High- and medium-Mn (H/M-Mn) base lightweight steels are a class of ultrastrong structural materials with high ductility compared to their low-Mn counterparts with low strength and poor ***, producing these H/M-Mn materials requires the advanced or high-tech manufacturing techniques, which can unavoidably provoke labor and cost concerns. Herein, we have developed a facilestrategy that circumvents the strength–ductility trade-off in low-Mn ferritic lightweight steels, by employing low-temperature tempering-induced partitioning (LTP). This LTP treatment affords a typical Fe-2.8Mn-5.7Al-0.3C (wt.%) steel with a heterogeneous size-distribution of metastable austenite embeddedin a ferrite matrix for partitioning more carbon into smaller austenite grains than into the larger austenite ones. This size-dependent partitioning results in slip plane spacing modification and lattice strain,which act through dislocation engineering. We ascribe the simultaneous improvement in strength andtotal elongation to both the size-dependent dislocation movement in austenite grains and the controlleddeformation-induced martensitic transformation. The low-carbon-partitioned large austenite grains increase the strength and ductility as a consequence of the combined martensitic transformation andhigh dislocation density-induced hardening and by interface strengthening. Additionally, high-carbonpartitioned small austenite grains enhance the strength and ductility by planar dislocation glide (inthe low strain regime) and by cross-slipping and delayed martensitic transformation (in the high strainregime). The concept of size-dependent dislocation engineering may provide different pathways for developing a wide range of heterogeneous-structured low-Mn lightweight steels, suggesting that LTP maybe desirable for broad industrial applications at an economic cost.

关键词： Low-Mn lightweight steel Carbon partitioning Metastable austenite Dislocation movement

Early-stage primary signet ring cell carcinoma of the colon

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World Journal of Gastroenterology 2013年第24期19卷 3895-3898页

作者： jae Hyun Kim Seun Ja Park Moo In Park Won Moon Sung eun Kim Department of Gastroenterology Kosin University College of Medicine

Primary signet ring cell carcinoma of the colorectum detected at an early stage is very rare; most cases are detected at an advanced stage. Therefore, its progno-sis is poorer than that of ordinary colorectal cancer. A 56-year-old Korean man was seen at this hospital for management of signet ring cell carcinoma of the co-lon. Colonoscopic examination revealed a Ⅱa-like, ill-defined and flatly elevated 9-mm residual tumor in the cecum. Endoscopic mucosal resection was preformed. Pathological examination of the resected specimen re-vealed signet ring cell carcinoma that had invaded the lamina propria without venous or perineural invasion. Abdominal computed tomography (CT) and positron CT showed no evidence of primary lesions or distant me-tastasis. An additional laparoscopic right-hemicolectomy was performed; no residual tumor or lymph node me-tastasis was found. We report a case of primary signet ring cell carcinoma of the colon detected at an early stage and provide a review of the literature.

关键词： Colon carcinoma Signet ring cell carcino-ma Primary carcinoma Early stage Endoscopic muco-sal resection