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Can the Honeymoon Foretell The Long-term Market Performance of IPO Firms in China?
Yong-Shang Liu,Sunghwan Kim 한국재무학회 2021 한국재무학회 학술대회 Vol.2021 No.11
Using 1,559 IPO firm data from the GSMAR database for 13 years from 2003 to 2015, we investigate the honeymoon effect of IPO and the impact of stock lock on long-term market performance of IPO firms with following results. Through this study, we found that firms with longer honeymoon periods have a better long-term market performance of IPO firms. This will lead firms to maintain their honeymoon period in various ways such as lock-up period. On contrary, our study found that higher lock-up stock period and Higher lock-up stock ratio will lead underperformance of IPO firms. The impact of lock-up stock on the stock market is complex and variable. Therefore, firms should consider short-term and long-term performance when setting stock lock periods. The disadvantage of this paper is that it only considered the honeymoon period, not the honeymoon return. This section will be supplemented in future studies.
Throughput-Delay Analysis of One-to-ManyWireless Multi-Hop Flows based on Random Linear Network
Shang, Tao,Fan, Yong,Liu, Jianwei The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.4
This paper addresses the issue of throughput-delay of one-to-many wireless multi-hop flows based on random linear network coding (RLNC). Existing research results have been focusing on the single-hop model which is not suitable for wireless multi-hop networks. In addition, the conditions of related system model are too idealistic. To address these limitations, we herein investigate the performance of a wireless multi-hop network, focusing on the one-to-many flows. Firstly, a system model with multi-hop delay was constructed; secondly, the transmission schemes of system model were gradually improved in terms of practical conditions such as limited queue length and asynchronous forwarding way; thirdly, the mean delay and the mean throughput were quantified in terms of coding window size K and number of destination nodes N for the wireless multi-hop transmission. Our findings show a clear relationship between the multi-hop transmission performance and the network coding parameters. This study results will contribute significantly to the evaluation and the optimization of network coding method.
Optimized Transformation of Streptomyces sp. ATCC 39366 Producing Leptomycin by Electroporation
Yong-Qiang Fan,Hong-Jian Liu,Li Yan,Yu-Shi Luan,Hai-Meng Zhou,Jun-Mo Yang,Shang-Jun Yin,Yu-Long Wang 한국미생물학회 2013 The journal of microbiology Vol.51 No.3
Streptomyces sp. ATCC 39366 produces leptomycin derivatives. Leptomycin B, a potent and specific inhibitor against the export of nuclear proteins, is the main product; however, the introduction of DNA into this strain is almost impossible, which has impeded its further use. We developed a Streptomyces sp. ATCC 39366 transformation protocol to introduce foreign DNA via electroporation. Various conditions were examined, including treatments of the cell wall with weakening agents, electroporation parameters, and DNA content. We found that only plasmid DNA isolated from a dam- ET12567 strain resulted in successful transformation. The mycelium growing in a yeast-peptone-dextrose medium supplemented with 1% glycine at 28°C on a rotary shaker (220 rpm) was more dispersed than those without supplementation and prone to electroporation. The maximum transformation efficiency of 8×102 CFU/μg plasmid DNA was obtained at a field strength of 13 kV/cm with a time constant of 13 ms (25-μF capacitor; parallel resistance, 600 Ω) using 1-mm electrocuvettes. The results of the transformations of two other Streptomyces species indicated that the optimized conditions established in this study might only be applicable to Streptomyces sp. ATCC 39366. However, this is the first report of successful transformation of Streptomyces sp. ATCC 39366, and will facilitate the construction of a gene knockout mutant in Streptomyces sp. ATCC 39366 to produce series of new leptomycin derivatives.
Xylaroisopimaranin A, a New Isopimarane Derivative from an Endophytic Fungus Xylaralyce sp.
Shang-Song Bao,Hui-Hui Liu,Xue-Qing Zhang,Cheng-Xiong Liu,Xiao-Cong Li,Zhi-Yong Guo 한국생약학회 2019 Natural Product Sciences Vol.25 No.3
Five secondary metabolites, including a new isopimarane derivative xylaroisopimaranin A (1), were isolated from the endophytic fungus Xylaralyce sp. (HM-1), and their structures were elucidated by 1D, 2D NMR, MS and CD spectra. Their bioactivities were performed to antibacterial, Hep G2 cells cytotoxicity and brine shrimp inhibition. The biological evaluation results showed that the xylaroisopimaranin A (1), xylabisboein B (2), griseofulvin (3) , 5-methylmellein (4) and mellein-5-carboxlic acid (5) displayed no significant Hep G2 cells cytotoxicity and antibacterial acitivity, but they inhibited the brine shrimp with IC50 from 0.5 to 25 μmol/mL.
Shang, Jing,Nian, Xiaohong,Liu, Yong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5
This study focuses on the coordination control problem of multiple electrical excited synchronous motor systems. A robust coordination controller is designed on the basis of cross coupling and an interval matrix. The proposed control strategy can deal with load uncertainty. In addition, the proposed control strategy is applied to a high-power metal-rolling system. Simulation and experiment results demonstrate that the proposed control strategy achieves good dynamic and static performance. It also shows better coordination performance than traditional proportional-integral controllers.
Performance Analysis and Optimization Design of Exhaust System for Turbocharging Diesel Engines
Liu Fushui,Sun Chenghan,Li Yikai,Shang Yong 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.3
Modern diesel engines are struggling to enhance the power density. This is usually realized by being equipped with a turbocharger, which demands higher performances on exhaust flow and exhaust waste energy recovery (WER). In the present study, we investigated the variations of exhaust flow and exhaust energy recovery performance with different geometrical parameters of exhaust system and proposed an evaluation and optimal design method of the exhaust system for a turbocharging diesel engine with a module pulse converter (MPC) system. The macro engine performances and the micro flow fields in exhaust system are obtained from the one/three dimensional (1D-3D) coupling simulation, and the energy of exhaust gas is quantified and analyzed with a concept of air power. It can be concluded that with a view to the exhaust performance and exhaust energy utilization, the diameter of the exhaust pipe should be set equal to the outlet diameter of the manifold and there is an optimized value of the contraction rate of the exhaust manifold. Besides, a parameter of the exhaust system called power potential coefficient is proposed to qualitatively evaluate the exhaust performance and exhaust energy.
Jing Shang,Xiaohong Nian,Yong Liu 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5
This study focuses on the coordination control problem of multiple electrical excited synchronous motor systems. A robust coordination controller is designed on the basis of cross coupling and an interval matrix. The proposed control strategy can deal with load uncertainty. In addition, the proposed control strategy is applied to a high-power metal-rolling system. Simulation and experiment results demonstrate that the proposed control strategy achieves good dynamic and static performance. It also shows better coordination performance than traditional proportional–integral controllers.
Tao Shang,Yong Fan,Jianwei Liu 한국통신학회 2013 Journal of communications and networks Vol.15 No.4
This paper addresses the issue of throughput-delay of one-to-many wireless multi-hop flows based on random linear network coding (RLNC). Existing research results have been focusing on the single-hopmodel which is not suitable for wireless multi-hop networks. In addition, the conditions of related system model are too idealistic. To address these limitations, we herein investigate the performance of a wireless multi-hop network, focusing on the oneto-many flows. Firstly, a system model with multi-hop delay was constructed; secondly, the transmission schemes of system model were gradually improved in terms of practical conditions such as limited queue length and asynchronous forwarding way; thirdly,the mean delay and the mean throughput were quantified in terms of coding window size K and number of destination nodes N for the wireless multi-hop transmission. Our findings show a clear relationship between the multi-hop transmission performance and the network coding parameters. This study results will contribute significantly to the evaluation and the optimization of network coding method.
Yu Jiyin,Liu Yong,Hua Xueni,Du Weifeng,Ning Chen,Ao Yuhui,Shang Lei 한국탄소학회 2022 Carbon Letters Vol.32 No.7
The evolvement in the microstructure and electrical properties of PAN-based carbon fibers during high-temperature carbonization were investigated. The study showed that as the heat treatment temperature increases, the change of carbon fiber resistivity around 1100 °C can be divided into two stages. In the first stage, the carbon content of the fiber increased rapidly, and small molecules such as nitrogen were gradually released to form a turbostratic of carbon crystal structure. The resistivity dropped rapidly from 3.19 × 10−5 Ω·m to 2.12 × 10−5 Ω·m. In the second stage, the carbon microcrystalline structure gradually became regular, and the electron movement area gradually became larger. At this time, the resistivity further decreases, from 2.12 × 10−5 Ω·m to 1.59 × 10−5 Ω·m. During carbonization, the tensile strength of carbon fiber first increased and then decreased. This is because the irregular and disordered graphite structure is formed first. As the temperature rose, the graphite layer spacing decreased and the grain thickness gradually increases. The modulus also gradually increased.