摘要 :
The role of venture capital who invested in China's listed companies on the Growth Enterprise Market (GEM) has been widely discussed in finance literature. There has been a great debate over whether VCs play a role of certificatio...
展开
The role of venture capital who invested in China's listed companies on the Growth Enterprise Market (GEM) has been widely discussed in finance literature. There has been a great debate over whether VCs play a role of certification or grandstanding. This paper investigates the role of VCs playing on IPOs by using the listed company data of GEM in China between October 2009 and April 2011. The empirical study shows that VCs who invested in the listed companies actually didn't played the role of certification but grandstanding. The further research shows as follows. First, the companies who are backed by VCs indicate significantly higher underpricing,which is consistent with the grandstanding hypothesis. Second, the more VCs invested in the companies, the less underpricing,or the lower the first-day return of IPO,which suggests that VC's motivation for grandstanding decreases. Third, the involvement of state-owned VCs in the companies, the less underpricing,or the lower firstday return of IPO,which also suggests that VC's motivation for grandstanding decreases. Fourth, the less experience of non-state-owned VCs for IPOs, the higher underpricing,or the higher first-day return of IPO, this actually implies that non-state-owned VCs have more motivation for grandstanding. Finally, according to the cost and benefit analysis of VCs' investment,we find that the reason behind VCs motivation for grandstanding is to pursue the "success myth" with huge gains,and this may result in VCs paying less attention on corporate governance, which in fact may lead to serious investment loss of the investors.
收起
摘要 :
The role of venture capital who invested in China's listed companies on the Growth Enterprise Market (GEM) has been widely discussed in finance literature. There has been a great debate over whether VCs play a role of certificatio...
展开
The role of venture capital who invested in China's listed companies on the Growth Enterprise Market (GEM) has been widely discussed in finance literature. There has been a great debate over whether VCs play a role of certification or grandstanding. This paper investigates the role of VCs playing on IPOs by using the listed company data of GEM in China between October 2009 and April 2011. The empirical study shows that VCs who invested in the listed companies actually didn't played the role of certification but grandstanding. The further research shows as follows. First, the companies who are backed by VCs indicate significantly higher underpricing,which is consistent with the grandstanding hypothesis. Second, the more VCs invested in the companies, the less underpricing,or the lower the first-day return of IPO,which suggests that VC's motivation for grandstanding decreases. Third, the involvement of state-owned VCs in the companies, the less underpricing,or the lower firstday return of IPO,which also suggests that VC's motivation for grandstanding decreases. Fourth, the less experience of non-state-owned VCs for IPOs, the higher underpricing,or the higher first-day return of IPO, this actually implies that non-state-owned VCs have more motivation for grandstanding. Finally, according to the cost and benefit analysis of VCs' investment,we find that the reason behind VCs motivation for grandstanding is to pursue the "success myth" with huge gains,and this may result in VCs paying less attention on corporate governance, which in fact may lead to serious investment loss of the investors.
收起
摘要 :
In recent years, electricity big data has extensive applications in the grid companies across the provinces. However, certain problems are encountered including, the inability to generate an ideal model using the isolated data pos...
展开
In recent years, electricity big data has extensive applications in the grid companies across the provinces. However, certain problems are encountered including, the inability to generate an ideal model using the isolated data possessed by each company, and the priority concerns for data privacy and safety during big data application and sharing. In this pursuit, the present research envisaged the application of federated learning to protect the local data, and to build a uniform model for different companies affiliated to the State Grid. Federated learning can serve as an essential means for realizing the grid-wide promotion of the achievements of big data applications, while ensuring the data safety.
收起
摘要 :
Big data application sharing supermarket is a big data application sharing portal. The first, one or more enterprise users can share and use the same big data application product. This product comes from the contribution of enterp...
展开
Big data application sharing supermarket is a big data application sharing portal. The first, one or more enterprise users can share and use the same big data application product. This product comes from the contribution of enterprise users of a certain sharing supermarket. In this way, we can solve the problem of unbalanced development of big data capabilities, and avoid repeated construction and repeated investment in the same kind of big data applications; the second. Through such a sharing platform, many enterprises carry out cooperation such as federal learning to jointly create big data application products.
收起
摘要 :
To ensure the accuracy and effectiveness of missile-borne star sensor for attitude determination, its optical axis direction must be adjusted in real time to avoid the stray light effectively and obtain star image with high-qualit...
展开
To ensure the accuracy and effectiveness of missile-borne star sensor for attitude determination, its optical axis direction must be adjusted in real time to avoid the stray light effectively and obtain star image with high-quality. In this paper, a fast optimal direction determination method that can be applied online in engineering is studied. Take the range of missile maneuver into consider, the proposed method solves the optimal direction of optical axis which can make star sensor obtain the best star image for star identification within the visible sky that avoids stray light. In the optical axis optimization model established, for a star sensor with given specification, the optimization indexes include the stars number and their mean magnitude of a star image obtained at a given direction, the control cost to reach the optimal direction from current status. The constraints include invisible sky, stray light etc. For such a complex nonlinear optimization problem without analytical solutions, the combination of enumeration method and table look-up method is employed to obtain solution rapidly for engineering applications. The stray light model is validated by comparing the simulation results with Satellite Tool Kit (STK). Simulation results show that the optimal direction determined by the proposed method can significantly improve the star image's quality and the optimization speed is fast enough to meet the requirement of online applications.
收起
摘要 :
To ensure the accuracy and effectiveness of missile-borne star sensor for attitude determination, its optical axis direction must be adjusted in real time to avoid the stray light effectively and obtain star image with high-qualit...
展开
To ensure the accuracy and effectiveness of missile-borne star sensor for attitude determination, its optical axis direction must be adjusted in real time to avoid the stray light effectively and obtain star image with high-quality. In this paper, a fast optimal direction determination method that can be applied online in engineering is studied. Take the range of missile maneuver into consider, the proposed method solves the optimal direction of optical axis which can make star sensor obtain the best star image for star identification within the visible sky that avoids stray light. In the optical axis optimization model established, for a star sensor with given specification, the optimization indexes include the stars number and their mean magnitude of a star image obtained at a given direction, the control cost to reach the optimal direction from current status. The constraints include invisible sky, stray light etc. For such a complex nonlinear optimization problem without analytical solutions, the combination of enumeration method and table look-up method is employed to obtain solution rapidly for engineering applications. The stray light model is validated by comparing the simulation results with Satellite Tool Kit (STK). Simulation results show that the optimal direction determined by the proposed method can significantly improve the star image's quality and the optimization speed is fast enough to meet the requirement of online applications.
收起
摘要 :
The flow and heat transfer characteristics were numerically investigated on a film cooling model under different rotating operating conditions. The computational model is originated from the mid-span section of a typical turbine r...
展开
The flow and heat transfer characteristics were numerically investigated on a film cooling model under different rotating operating conditions. The computational model is originated from the mid-span section of a typical turbine rotor with two rows of 14 staggered injection holes angled 30° both on the suction surface and pressure surface, and the flow through the coolant plenum and all the hole-pipes are resolved as a part of the computational domain by specifying the coolant mass flux in the plenum. The computations primarily focus on understanding the rotational effect on film cooling performance in mechanism research approach. In the present study, the Reynolds number (Re) based on mainstream velocity and injection hole diameter varies from 1835.5 to 5507.4, and the averaged blowing ratio (M) ranges of 0.5 to 1.5. Results show that the coolant will move on to the high-radius locations near the suction and pressure surfaces due to the strong centrifugal effect, which leads to the decrease in adiabatic effectiveness accordingly. The discharge coefficients (Cd), on the pressure surface, are much higher than that on the suction surface under a given operating condition. In addition, the critical values of angular speed which represent the equilibrium of centrifugal force and Coriolis force near the pressure surface are also presented.
收起
摘要 :
This article combines users' attitudes towards life, car values, and users' ratings of new energy configurations to build a new energy vehicle configuration recommendation model. First, determine the data source, and process the d...
展开
This article combines users' attitudes towards life, car values, and users' ratings of new energy configurations to build a new energy vehicle configuration recommendation model. First, determine the data source, and process the data for outliers and missing values, use the Pearson correlation coefficient to calculate the correlation coefficient matrix between users. The coefficient matrix is combined with density clustering to cluster the users; secondly, the comprehensive similarity between the new energy vehicle configurations is calculated, and the density clustering is also used to cluster the configurations; Then, construct a mapping table for users to score configurations based on the clustering results between users and configurations; finally, use matrix factorization technology to make predictions, and give recommended configurations based on the prediction results.
收起
摘要 :
This article combines users' attitudes towards life, car values, and users' ratings of new energy configurations to build a new energy vehicle configuration recommendation model. First, determine the data source, and process the d...
展开
This article combines users' attitudes towards life, car values, and users' ratings of new energy configurations to build a new energy vehicle configuration recommendation model. First, determine the data source, and process the data for outliers and missing values, use the Pearson correlation coefficient to calculate the correlation coefficient matrix between users. The coefficient matrix is combined with density clustering to cluster the users; secondly, the comprehensive similarity between the new energy vehicle configurations is calculated, and the density clustering is also used to cluster the configurations; Then, construct a mapping table for users to score configurations based on the clustering results between users and configurations; finally, use matrix factorization technology to make predictions, and give recommended configurations based on the prediction results.
收起
摘要 :
The signal peptides prediction algorithm SignalP v3.0, subcellular protein location prediction algorithm TargetP.vl.l, potential GPI-anchor sites prediction algorithm big-PI predictor, trans-membrane domains prediction algorithm T...
展开
The signal peptides prediction algorithm SignalP v3.0, subcellular protein location prediction algorithm TargetP.vl.l, potential GPI-anchor sites prediction algorithm big-PI predictor, trans-membrane domains prediction algorithm TMHMM v2.0 and bioinformatics algorithm MEME were used to analyze 16446 protein sequences of Botrytis cinerea. The results showed that there were 579 deduced secretary proteins. Among these proteins, the minimum and maximum of open read frame were 102 bp and 4848 bps respectively and mean score was 1271 bps. The signal peptides' length was concentrated to 16-39 amino acids and the average length was 21. 122 of these proteins contain the highly conserved host-targeting-motif RxLx within 100 residues adjacent to the signal peptide cleavage site. According to PEDNAT and COG of GenBank database, this motif s functions include metabolism modification and cell secretion etc. We blast those putative secretary proteins with RxLx motif in GenBenk and found 47.54% of them have highly conserved homologues in other species, among them 74.1% have putative protein domains. This means these proteins may be more stable or earlier origin. We suppose these proteins are candidate participating in the pathogenesis of Botrytis cinerea but we still need more experimental evidence to confirm their definite functions.
收起
原文获取