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A novel method for PAPR reduction of the OFDM signal using nonlinear scaling and FM

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Frontiers of Information Technology & Electronic Engineering 2019年第11期20卷 1587-1594页

作者： Yi-hu XU Jung-Yeol OH Zhen-hao SUN myoung-seob lim Deptarment of Communication Engineering Yanbian UniversityYanji 133002China Electronics and Telecommunications Research Institute(ETRI) Daejeon 305-700Republic of Korea Division of Electronics&Information Engineering Chonbuk National UniversityJeonj 561-756Republic of Korea

Orthogonal frequency division multiplexing (OFDM) has been adopted as standard beginning with the 4th generation mobile communication system because of its high-bit-rate transmission capability under frequency selective fading channel con-ditions. However, a major disadvantage of OFDM is the non-constant envelope signal with a high peak-to-average power ratio (PAPR). The high peak signal in OFDM is distorted through a nonlinear amplifier, which causes bit error ratio (BER) reduction. Many techniques have been developed for reducing PAPR at the cost of inefficient bandwidth usage or throughput because of the additional information about PAPR reduction. We propose a novel method, in which the high peak signal above the threshold of the nonlinear amplification region is nonlinearly downscaled to lower the PAPR. The time slot location and scaling ratio for where and how the high peak baseband OFDM signal is downscaled are transmitted using frequency modulation (FM) combined with OFDM, which requires less additional bandwidth than the previously proposed methods. Simulation results show that the pro-posed novel method provides a lower PAPR and elicits a better BER performance compared with other conventional methods, because it reduces the PAPR by nonlinear scaling and restores the pre-distorted signal using FM.

关键词： Orthogonal frequency division multiplexing Peak-to-average power ratio Nonlinear scaling Frequency modulation

Alamouti Transmit Diversity Scheme with A Simple Diagonal Weighting Matrix

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Alamouti Transmit Diversity Scheme with A Simple Diagonal We...

Determination of efficient superfinishing conditions for mirror surface finishing of titanium

IEEE 2005 International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications

作者： Jiaen Li, Student Member, IEEE, myoung seob lim Division of Electronics & Information Engineering, Chonbuk National University

In this paper, a novel scenario of the Alamouti’s space-time block code (STBC) system combined with a simple diagonal weighting matrix is presented. The diagonal weighting matrix is performed at the t

关键词： Space-time block code, weighting matrix, bit-error rate, transmit diversity.

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Journal of Central South University 2012年第1期19卷 155-162页

作者： KIM Jin-seob lim Eun-seong JUNG Yoon-gyo School of Mechatronics Changwon National UniversityChangwon 641-773Korea

To determine mirror surface finishing conditions and efficient and economical superfinishing conditions for pure titanium and titanium alloys, an abrasive film is used when superfinishing is performed under varying conditions. These conditions include the workpiece rotation speed, the oscillation speed, the contact pressure of the roller, the hardness of the roller, and the type of abrasive film. The superfinishing device is applied to polishing a thin and long cylindrical bar. A micro-finishing film and a lapping film were used as abrasive films. A1203 grains or SiC grains were used as abrasives. The surface roughness of a polished workpiece was measured using a stylus-type surface-roughness measuring instrument. As a result, the conditions to improve the polishing surface efficiently include high values for the workpiece rotation speed, oscillation speed and contact pressure. The roller hardness has no effect on the efficient polishing conditions. The mirror finish of a surface can be created using lapping film of 3 μm with Al2O3 grains after polishing to a steady surface roughness under the efficient polishing conditions.

关键词： superfinishing mirror surface finishing abrasive film surface roughness titanium optimal polishing time

Analytical method development of pregabalin and related substances in extended release tablets containing polyethylene oxide

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Asian Journal of Pharmaceutical Sciences 2016年第1期11卷 229-230页

作者： Jin seob Oh Seo Hyun lim Sung Ha Ryu Kyung Hun Kim Kyung Soo Lee Woo Heon Song Jun Sang Park GL PharmTech Corporation

Pregabalin,(S)-3-amino methyl hexanoic acid,is a structural analogue ofγ-amino butyric acid(GABA)which has been widely used to treat partial seizures and neuropathic pain[1].It is soluble in aqueous solution and sparingly soluble in organic solvents such as ethanol,DMSO and *** oxide(PEO)has a strong negative effect on analysis of hydrophilic active ingredient and its relative substances due to extremely high viscosity of PEO in aqueous *** aim of this study is to develop a fast and precise method for the determination of pregabalin and its relative substances in extended release tablets including PEO using sodium sulfate for the treatment of sample solution.

关键词： Pregabalin Polyethylene oxide Related compound HPLC

Magnetic resonance evaluation of human mesenchymal stem cells in corpus cavernosa of rats and rabbits

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Asian Journal of Andrology 2007年第3期9卷 361-367页

作者： Yun-seob Song Ja-Hyeon Ku Eun-Seop Song Jung-Hoon Kim Jin-Suck Jeon Kong-Hee Lee Sook-Ja Kim Hee-Jeong Cheong Ik-Sung lim Dongho Choi Jong-Ho Won Department of Urology Stem Cell therapy Center Soonchunhyang School of Medicine Seoul 140-743 Korea Department of Urology Seoul National University Hospital Seoul 110-744 Korea Department of Obstetrics and Gynecology Inha University School of Medicine Incheon 400-103 Korea Department of Radiology Soonchunhyang School of Medicine Seoul 140-743 Korea Department of Internal Medicine Soonchunhyang School of Medicine Seoul 140-743 Korea Department of Urology Soonchunhyang School of Medicine Seoul 140-743 Korea Stem Cell therapy Center Soonchunhyang School of Medicine Seoul 140-743 Korea Department of Industrial Management ＆ Engineering Namseoul University College of Engineering Cheonan 330-707 Korea Department of Surgery Stem Cell therapy Center Soonchunhyang School of Medicine Seoul 140-743 Korea Department of Internal Medicine Stem Cell therapy Center Soonchunhyang School of Medicine Seoul 140-743 Korea

Aim： To investigate whether the biological process of superparamagnetic iron oxide （SPIO）-labeled human mesenchymal stem cells （hMSCs） may be monitored non-invasively by using in vivo magnetic resonance （MR） imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits. Methods： The labeling efficiency and viability of SP10-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period. Results： hMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than lx 105 concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections. Conclusion： SP10-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.

关键词： human mesenchymal stem cells magnetic resonance stem cells penis cell labeling corpus cavemosa

Development of controlled release bi-layered tablets containing oxycodone hydrochloride

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Asian Journal of Pharmaceutical Sciences 2016年第1期11卷 178-178页

作者： Kyung Hun Kim Kyung Soo Lee Il Woo Jung Jin seob Oh Seo Hyun lim Sung Hoon Lee Woo Heon Song Jun Sang Park GLPharmTech Corporation #714JungangInduspia V137Sagimakgol-roJungwon-guSeongnamGyeonggidoRepublic of Korea Department of Pharmaceutical Engineering Cheongju University298Daeseong-roCheongwon-guCheongjuChungcheongbuk-doRepublic of Korea

Oxycodone hydrochloride is a semi-synthetic opioid agonist that provides very effective relief for moderate to severe pain in cancer and post-operative patients. Controlled release oxycodone formulations have been studied to enhance the therapeutic effect by providing constant release over the whole dosing interval and improve patient’s convenience by reducing the frequency of administration as well.

关键词： Oxycodone Control release Bi-layered tablet IVIVC