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Characteristics analysis and library development for piezoelectric transformer to drive a ballast for a 35 W class fluorescent lamp using PSPICE modeling

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Journal of Central South University 2016年第1期23卷 169-180页

作者： kim young-Choon Division of Mechanical and Automotive Engineering College of Engineering Kongju National University

PSPICE model driven by an electric equivalent circuit of a piezoelectric circuit is presented. In order to confirm this model to be effective, an independent model of cold cathode fluorescent lamp(CCFL) driving circuit is used to conduct simulations, leading to a precise modeling. A library is configured through modeling and its accuracy is verified through simulations for widely used and representative lamps such as CCFL, fluorescent lamps, HID lamps, and electrodeless fluorescent lamps. On the basis of experiments, a lamp simulation is also performed using PSPICE, which allows us to take advantage of the lamp library easily. Also, PSPICE model driven by an electric equivalent circuit of a piezoelectric transformer is presented. In order to confirm this model to be effective, an independent model of CCFL driving circuit is used to conduct simulations, leading to a precise modeling. In addition, a new type of electronic ballast is proposed, which allows 35 W-class(T5-class) fluorescent lamp to work. This system is built by a rectifier which has improved power factor and half-bridge series resonant inverter. Also, with size of 27.5 mm high, 27.5 mm wide and 2.5 mm thick, the produced piezoelectric transformer has a high step-up ratio, through which it is possible for the electric ballast circuit to be lighter, smaller and more efficient. After the produced ballast is used to drive the fluorescent lamp for 25 min, it yields 0.95 in power factor correction, 86% in efficiency, 35.07 W in output voltage and 20.5 °C in temperature increase while meeting the characteristics of the 35 W-class fluorescent lamp.

关键词： PSPICE 35 W-class cold cathode fluorescent lamp (CCFL) fluorescent lamp library

Combination-based nanomaterial designs in single and double dimensions for improved electrodes in lithium ion-batteries and faradaic supercapacitors

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Journal of Energy Chemistry 2019年第11期28卷 119-146页

作者： Tuyet Nhung Pham Duckshin Park Yongil Lee il Tae kim Jaehyun Hur You-Kwan Oh young-Chul Lee Department of BioNano Technology Gachon University1342 SeongnamdaeroSujeong-guSeongnam-siGyeonggi-do 13120Republic of Korea Korea Railroad Research Institute(KRRI) 176 Cheoldobakmulkwan-roUiwang-si 16105Gyeonggi-doRepublic of Korea Department of Chemical and Biological Engineering Gachon UniversitySeongnam-siGyeonggi-do 13120Republic of Korea School of Chemical and Biomolecular Engineering Pusan National UniversityBusan 46241Republic of Korea

In the past decade, researchers in the fields of energy production have concentrated on the improvement of new energy storage devices. Lithium-ion batteries(LIBs) and faradaic supercapacitors(FSs) have attracted special attention as a result of the rapid development of new electrode nanomaterials, especially hybrid nanomaterials, which can meet the increasingly higher requirements for future energy, such as the capability to deliver high-power performance and an extremely long life cycle. In these hybrid nanostructures, a series of synergistic effects and unique properties arising from the combination of individual components are a major factor leading to improved charge/discharge capability, energy density, and system lifetime. This paper describes the most recent progress in the growth of hybrid electrode materials for LIBs and FSs systems, focusing on the combination of zero-dimensional(0 D), one-dimensional(1 D), two-dimensional(2 D), and three-dimensional(3 D) nanomaterials, respectively.

关键词： Hybrid nanomaterials Synergistic effects Zero-dimensional nanomaterials One-dimensional nanomaterials Two-dimensional nanomaterials Three-dimensional nanomaterials

Flash‑Induced High‑Throughput Porous Graphene via Synergistic Photo‑Effects for Electromagnetic Interference Shielding

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Nano-Micro Letters 2023年第11期15卷 1-18页

作者： Jin Soo Lee Jeong‑Wook kim Jae Hee Lee Yong Koo Son young Bin kim Kyoohee Woo Chanhee Lee il‑Doo kim Jae young Seok Jong Won Yu Jung Hwan Park Keon Jae Lee Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak‑roYuseong‑guDaejeon 34141Republic of Korea School of Electrical Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak‑roYuseong‑guDaejeon 34141Republic of Korea Department of Printed Electronics Nano‑Convergence Manufacturing Systems Research DivisionKorea Institute of Machinery and Materials(KIMM)156 Gajeongbuk‑RoYuseong‑GuDaejeon 34103Republic of Korea Department of Mechanical System Design Engineering Seoul National University of Science and Technology232 Gongneung‑roNowon‑guSeoul 01811Republic of Korea Department of Mechanical Engineering(Department of Aeronautics Mechanical and Electronic Convergence Engineering)Kumoh National Institute of Technology61 Daehak‑roGumiGyeongbuk 39177Republic of Korea

Porous 2D materials with high conductivity and large surface area have been proposed for potential electromagnetic interference(EMI)shielding materials in future mobility and wearable applications to prevent signal noise,transmission inaccuracy,system malfunction,and health ***,we report on the synthesis of lightweight and flexible flash-induced porous graphene(FPG)with excellent EMI shielding *** broad spectrum of pulsed flashlight induces photo-chemical and photo-thermal reactions in polyimide films,forming 5×10 cm^(2)-size porous graphene with a hollow pillar structure in a few *** resulting material demonstrated low density(0.0354 g cm^(−3))and outstanding absolute EMI shielding effectiveness of 1.12×10^(5) dB cm^(2) g^(−1).The FPG was characterized via thorough material analyses,and its mechanical durability and flexibility were confirmed by a bending cycle ***,the FPG was utilized in drone and wearable applications,showing effective EMI shielding performance for internal/external EMI in a drone radar system and reducing the specific absorption rate in the human body.

关键词： Porous graphene Flash lamp Photo-pyrolysis High-throughput Electromagnetic interference shielding

Effect of dietary vitamin C on gastric cancer risk in the Korean population

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World Journal of Gastroenterology 2016年第27期22卷 6257-6267页

作者： Bach Viet Hoang Jeonghee Lee il Ju Choi young-Woo kim Keun Won Ryu Jeongseon kim Department of Cancer Control and Policy Graduate School of Cancer Science and Policy National Cancer Center Molecular Epidemiology Branch Research Institute National Cancer Center Center for Gastric Cancer National Cancer Center Hospital National Cancer Center

AIM: To investigate the effects of dietary vitamin C and foods containing vitamin C on gastric cancer ***: Our study included 830 control subjects and 415 patients. Data regarding demographics, medical history, and lifestyle, including dietary and nutrient intake, were collected using reliable selfadministered questionnaires. Dietary intake information was collected from the participants using a food frequency questionnaire that has been previously reported as reliable and valid. A rapid urease test and a histological evaluation were used to determine the presence of Helicobacter pylori(H. pylori) infection. Twenty-three vitamin C-contributing foods were selected, representing over 80% of the cumulative vitamin C contribution. RESULTS: In analyses adjusted for first-degree family history of gastric cancer, education level, job, household income, smoking status, and regular exercise, an inverseassociation between vitamin C intake and gastric cancer risk was observed for the highest(≥ 120.67 mg/d) vs the lowest(< 80.14 mg/d) intake category [OR(95%CI): 0.64(0.46-0.88)], with a significant trend across the three intake categories(P = 0.007). No protective effect of vitamin C was detected after stratification by gender. No effect of vitamin C intake on the gastric cancer incidence was found in either men or women infected with H. pylori. Vitamin C-contributing foods, including cabbage [0.45(0.32-0.63), 0.50(0.34-0.75), 0.45(0.25-0.81)], strawberries [0.56(0.40-0.78), 0.49(0.32-0.74), 0.52(0.29-0.93)], and bananas [0.40(0.29-0.57), 0.41(0.27-0.62), 0.34(0.19-0.63)], were protective factors against the risk of gastric cancer based on the results of the overall adjusted analyses and the results for men and women, ***: A protective effect of vitamin C and vitamin C-contributing foods against gastric cancer was observed. Further studies using larger sample sizes are required to replicate our results.

关键词： Vitamin C Vitamin C-contributing foods Helicobacter pylori Gastric cancer Korean population

Etching characteristics and surface modification of InGaSnO thin films under Cl_(2)/Ar plasma

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Plasma Science and Technology 2023年第10期25卷 91-96页

作者： young-Hee JOO Jae-Won CHOI Bo HOU Hyuck-In KWON Doo-Seung UM Chang-il kim Department of Electronic and Electrical Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Firearms and Optics Daeduk UniversityDaejeon 34111Republic of Korea School of Physics and Astronomy Cardiff UniversityCardiff CF243AAUnited Kingdom Department of Electrical Engineering Sejong UniversitySeoul 05006Republic of Korea

Indium gallium tin oxide(IGTO)thin films have the potential for high mobility and lowtemperature processing,which makes them suitable for applications such as display backplanes and high-voltage switching ***,very few studies have investigated the plasmaetching characteristics of IGTO and changes in its properties after *** this study,the etching characteristics of IGTO were investigated using Cl_(2)/Ar plasma,and changes in surface properties were *** showed that the etch rate increased with an increase in the proportion of Cl_(2),with the highest etch rate observed at 69 nm min^(-1)in pure Cl_(2)plasma with a gas flow rate of 100 ***,increased radio-frequency power caused a rise in the etch rate,while a process pressure of 15 m Torr was *** primary etching mechanism for IGTO thin films under Cl_(2)plasma was a chemical reaction,and an increased work function indicated the occurrence of defects on the *** addition,the etching process reduced the surface roughness of Cl_(2)-containing plasma,whereas the etching process in pure Ar plasma increased surface *** study contributes to a better understanding of the plasmaetching characteristics of IGTO and changes in its properties after etching,providing valuable insights for IGTO-based applications.

关键词： InGaSnO Cl2-based plasma etching mechanism surface modification plasma etching

Design of small-area and high-efficiency DC-DC converter for 1 T SRAM

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Journal of Central South University 2012年第2期19卷 417-423页

作者： LEE Jae-hyung 金丽妍余忆宁 JANG Ji-hye kim Kwang-il HA Pan-bong kim young-hee Department of Electronic Engineering Changwon National University9 Sarim-Dong

The direct current-direct current （DC-DC） converter is designed for 1 T static random access memory （SRAM） used in display driver integrated circuits （ICs）, which consists of positive word-line voltage （VpwL）, negative word-line voltage （VinyL） and half-VDD voltage （VHDo） generator. To generate a process voltage temperature （PVT）-insensitive VpWL and VNWL, a set of circuits were proposed to generate reference voltages using bandgap reference current generators for respective voltage level detectors. Also, a VOWL regulator and a VNWL charge pump were proposed for a small-area and low-power design. The proposed VpwL regulator can provide a large driving current with a small area since it regulates an input voltage （VCI） from 2.5 to 3.3 V. The VmvL charge pump can be implemented as a high-efficiency circuit with a small area and low power since it can transfer pumped charges to VNWL node entirely. The DC-DC converter for 1 T SRAM were designed with 0.11 μm mixed signal process and operated well with satisfactory measurement results.

关键词： 1 T-static random access memory direct current-direct current converter positive word-line voltage negative word-line voltage half- VDb generator

Characteristics of Algal Succession Following Rock Scraping at Imwon Area in the East Coast of Korea

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Journal of Ocean University of China 2016年第6期15卷 1087-1093页

作者： young Dae kim Jung Kwan Alan Myung Mo Nam Chu Lee Hyun il Yoo Su Yeoung Yeon young Hwan kim Jang Kyun kim Jae Suk Choi East Sea Fisheries Research Institute National Fisheries Research & Development Institute Gangneung 210-860Republic of Korea Korea National Park Service National Park Research Institute Yeosu 550-833 Republic of Korea Seaweed Research Center 1rational Fisheries Research & Development lnstituie Mokpo 530-831 Republic of Korea Department of Biology Chungbuk National University Chongju 361-763 Republic Of Korea Department of Marine Science School of Natural Sciences Incheon National University 22012 Yeonsu-gu Incheon Korea Department of Marine Sciences University of Connecticut 06901 Stamford Connecticut USA Division of Bioindustry Silla University Sasang-gu Busan 617-736 Republic of Korea

Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin bar- ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per- centage and importance value （IV） of erustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae （mean IV=62%） as well as Sargassum sp. （mean IV=28%）, and Gelidium amansii （mean IV= 19%） were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii （mean IV = 32%） underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di- verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.

关键词： algal succession sea-urchin barren ground rock scraping subtidal zone

Dual-priming oligonucleotide-based multiplex PCR using tissue samples in rapid urease test in the detection of Helicobacter pylori infection

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World Journal of Gastroenterology 2014年第21期20卷 6547-6553页

作者： Woo Chul Chung Sung Hoon Jung Jung Hwan Oh Tae Ho kim Dae young Cheung Byung Wook kim Sung Soo kim Jin il kim Eun young Sin Department of Internal Medicine the Catholic University of KoreaSeoul 130-709South Korea The Research Institute of St. Vincent Hospital the Catholic University of KoreaSuwon 442-723South Korea

AIM: To investigate whether tissue samples processed by the rapid urease test (RUT) kit are suitable for dual-priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) to detect Helicobacter pylori (... 详细信息

关键词： Helicobacter pylori Diagnosis Dual-priming oligonucleotide-based multiplex polymerase chain reaction

Optimal Center-of-Mass Pivot Effect of Spinal Motion in Feline Galloping

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Journal of Bionic Engineering 2020年第5期17卷 970-977页

作者： young Kook kim Dongwon Yun LV R&D team Electro-technology R&D CenterLS ELECTRIC Co.LtdCheongju 28437South Korea Department of Robotics Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988South Korea

In this paper,we studied the acceleration behavior of a quadruped animal during a galloping *** the development of many quadruped robotic systems has been focused on dynamic movements,it is obvious that guidance from the dynamic behavior of quadruped animals is needed for robotics *** fulfill this demand,this paper deals with analysis of the galloping motions of a domestic cat,which is well known for its excellent acceleration performance among four-legged *** on the planar motion capture environment,the movement data of a galloping feline was acquired and the dynamic motions were estimated using a spring-mass *** particular,the effects of the position and angle of the center-of-mass of the cat,angular displacement of the spine,and angular velocity of the spine were analyzed and are discussed *** this process,it was possible to understand the dynamic movement characteristics of the cat,and to understand the relationships between,and the influences of,these *** this analysis,we provide significant data applicable to the design of joint movements in quadruped robot systems.

关键词： quadrupedalism feline galloping domestic cat center-of-mass