Mergers ＆ acquisitions （M＆As） are important strategic instruments, yet nearly half of all transactions fail, often resulting in disastrous write-offs and losses for corporations and financing institutions alike - ...Mergers ＆ acquisitions （M＆As） are important strategic instruments, yet nearly half of all transactions fail, often resulting in disastrous write-offs and losses for corporations and financing institutions alike - despite promising prospects upfront. Applied research has been trying to find a ＂panacea＂ to prevent or at least predict M＆A failure, investigating motives, synergies and performance. Despite the growing unease with the stationary explanatory models in literature, research has only marginally focused on the concept of time, with inquiries into market timing and integration speed. Yet other timing concepts have been neglected in concepts so far despite early empirical evidence for their existence. The purpose of this paper is thus to identify and elaborate on the importance of further relevant theories of timing. For this, and true to the exploratory nature of the topic, the authors have chosen a qualitative comparative case study design based on existing case reports which are investigated for narrations highlighting timing concepts. This study reveals six factors which have a crucial impact on the M＆A outcome： time of acquisition, M＆A duration in its entirety, M＆A sequence, synergy chronology, frequency of acquisitions and time to step back. It contributes to theory and practice in outlining the careful attention that needs to be paid in planning in these factors to enhance the chances of a successful M＆A transaction.展开更多
Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) t...Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) theory was proposed.Sensing asynchronously,each cognitive user calculated the confidence measure functions with double threshold spectrum sensing method.When the useful report was received by the fusion center,a fusion process would be triggered.Then the sensing results were fused together based on D-S theory.The analysis and simulation results show that the proposed scheme can improve the spectrum sensing efficiency and reduce the calculation amount of the fusion center compared with the existing schemes.展开更多
OBJECTIVE It has been recognized that HBV infection and alcohol consumption are two important risk factors for primary hepatocellular carcinoma （HCC）. Recently, the role of clonorchiasis as a risk factor for HCC is ...OBJECTIVE It has been recognized that HBV infection and alcohol consumption are two important risk factors for primary hepatocellular carcinoma （HCC）. Recently, the role of clonorchiasis as a risk factor for HCC is controversial. We aimed to investigate whether these factors increase the risk of HCC in Guangxi, China. METHODS A hospital-based, case-control study of HCC was conducted from July 2005 to July 2007. We enrolled 500 consecutive patients with HCC as an experimental group and 500 patients without tumor in liver as a control group. The risk factors that the patients were exposed to were assessed. RESULTS Comparing the risks of developing the HCC, we found out the following results. The risk of developing HCC for the patients with clonorchiasis was 5 folds of that for the patients without clonorchiasis （OR = 5.0; 95% CI： 3.1-8.1）, and the risk for the patients with alcohol consumption was 3 folds of that for the patients without drinking alcohol （OR = 3.4; 95% CI： 2.3-4.9）, and similarly, the risk for the patients with HBV infection was 21 times of that for the patients without HBV infection （OR = 20.6; 95% CI： 14.3-29.7）. According to crossover analysis, there was significant interaction among clonorchiasis, HBV infection and alcohol consumption, with synergistic indices greater than 1. The etiologic fractions attributed to these interactions [EF （A × B）] are 0.7465, 0.5789 and 0.5506, respectively. CONCLUSION Clonorchiasis, HBV infection and heavy alcohol consumption are independent risk factors for developing HCC in our population in Guangxi, and as they can interact synergistically, the risk of developing HCC is increased. Data from this study may indicate new prevention strategies of developing HCC in high-risk individuals.展开更多
针对传统同时定位与地图构建(simultaneous localization and mapping,SLAM)框架面临动态场景时产生明显定位误差,建立的场景稠密地图会包含动态对象及其运动叠影,从而导致定位与建图鲁棒性不足的问题,面向以人类为主要动态对象的室内...针对传统同时定位与地图构建(simultaneous localization and mapping,SLAM)框架面临动态场景时产生明显定位误差,建立的场景稠密地图会包含动态对象及其运动叠影,从而导致定位与建图鲁棒性不足的问题,面向以人类为主要动态对象的室内动态场景,从“温度”的角度出发,提出基于热像仪与深度相机结合的多传感SLAM协同方案,解决室内动态场景中的定位与建图难题。首先,建立一套针对热像仪与深度相机的联合标定策略,重新设计标定板与标定方案,完成相机的内参标定、外参标定与图像配准,得到一一对应的RGB、深度、热(RDH)三模图像;其次,由热图像得到人体掩模图像,进而在ORB-SLAM2系统框架下构建静态特征提取与数据关联策略,实现基于三模图像的视觉里程计;然后,基于人体掩模图像更新深度图像,滤除人体区域,进而完成基于三模图像的静态环境稠密地图构建;最后,在室内动态场景下进行实验验证,结果表明所提出算法在室内动态场景下可有效剔除动态对象的干扰特征,相对传统SLAM算法具有明显优势。展开更多
As one of the major contributions of biology to competitive decision making, evolutionary game theory provides a useful tool for studying the evolution of cooperation. To achieve the optimal solution for unmanned aeri...As one of the major contributions of biology to competitive decision making, evolutionary game theory provides a useful tool for studying the evolution of cooperation. To achieve the optimal solution for unmanned aerial vehicles （UAVs） that are car- rying out a sensing task, this paper presents a Markov decision evolutionary game （MDEG） based learning algorithm. Each in- dividual in the algorithm follows a Markov decision strategy to maximize its payoff against the well known Tit-for-Tat strate- gy. Simulation results demonstrate that the MDEG theory based approach effectively improves the collective payoff of the roam. The proposed algorithm can not only obtain the best action sequence but also a sub-optimal Markov policy that is inde- pendent of the game duration. Furthermore, the paper also studies the emergence of cooperation in the evolution of self-regarded UAVs. The results show that it is the adaptive ability of the MDEG based approach as well as the perfect balance between revenge and forgiveness of the Tit-for-Tat strategy that the emergence of cooperation should be attributed to.展开更多
文摘Mergers ＆ acquisitions （M＆As） are important strategic instruments, yet nearly half of all transactions fail, often resulting in disastrous write-offs and losses for corporations and financing institutions alike - despite promising prospects upfront. Applied research has been trying to find a ＂panacea＂ to prevent or at least predict M＆A failure, investigating motives, synergies and performance. Despite the growing unease with the stationary explanatory models in literature, research has only marginally focused on the concept of time, with inquiries into market timing and integration speed. Yet other timing concepts have been neglected in concepts so far despite early empirical evidence for their existence. The purpose of this paper is thus to identify and elaborate on the importance of further relevant theories of timing. For this, and true to the exploratory nature of the topic, the authors have chosen a qualitative comparative case study design based on existing case reports which are investigated for narrations highlighting timing concepts. This study reveals six factors which have a crucial impact on the M＆A outcome： time of acquisition, M＆A duration in its entirety, M＆A sequence, synergy chronology, frequency of acquisitions and time to step back. It contributes to theory and practice in outlining the careful attention that needs to be paid in planning in these factors to enhance the chances of a successful M＆A transaction.
基金Science and Technology Projects of Xuzhou City,China(No.XX10A001)Jiangsu Provincial National Natural Science Foundation of China(No:BK20130199)
文摘Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) theory was proposed.Sensing asynchronously,each cognitive user calculated the confidence measure functions with double threshold spectrum sensing method.When the useful report was received by the fusion center,a fusion process would be triggered.Then the sensing results were fused together based on D-S theory.The analysis and simulation results show that the proposed scheme can improve the spectrum sensing efficiency and reduce the calculation amount of the fusion center compared with the existing schemes.
基金supported by a grant from the National Natural Science Foundation of China(No.30660162).
文摘OBJECTIVE It has been recognized that HBV infection and alcohol consumption are two important risk factors for primary hepatocellular carcinoma （HCC）. Recently, the role of clonorchiasis as a risk factor for HCC is controversial. We aimed to investigate whether these factors increase the risk of HCC in Guangxi, China. METHODS A hospital-based, case-control study of HCC was conducted from July 2005 to July 2007. We enrolled 500 consecutive patients with HCC as an experimental group and 500 patients without tumor in liver as a control group. The risk factors that the patients were exposed to were assessed. RESULTS Comparing the risks of developing the HCC, we found out the following results. The risk of developing HCC for the patients with clonorchiasis was 5 folds of that for the patients without clonorchiasis （OR = 5.0; 95% CI： 3.1-8.1）, and the risk for the patients with alcohol consumption was 3 folds of that for the patients without drinking alcohol （OR = 3.4; 95% CI： 2.3-4.9）, and similarly, the risk for the patients with HBV infection was 21 times of that for the patients without HBV infection （OR = 20.6; 95% CI： 14.3-29.7）. According to crossover analysis, there was significant interaction among clonorchiasis, HBV infection and alcohol consumption, with synergistic indices greater than 1. The etiologic fractions attributed to these interactions [EF （A × B）] are 0.7465, 0.5789 and 0.5506, respectively. CONCLUSION Clonorchiasis, HBV infection and heavy alcohol consumption are independent risk factors for developing HCC in our population in Guangxi, and as they can interact synergistically, the risk of developing HCC is increased. Data from this study may indicate new prevention strategies of developing HCC in high-risk individuals.
文摘针对传统同时定位与地图构建(simultaneous localization and mapping,SLAM)框架面临动态场景时产生明显定位误差,建立的场景稠密地图会包含动态对象及其运动叠影,从而导致定位与建图鲁棒性不足的问题,面向以人类为主要动态对象的室内动态场景,从“温度”的角度出发,提出基于热像仪与深度相机结合的多传感SLAM协同方案,解决室内动态场景中的定位与建图难题。首先,建立一套针对热像仪与深度相机的联合标定策略,重新设计标定板与标定方案,完成相机的内参标定、外参标定与图像配准,得到一一对应的RGB、深度、热(RDH)三模图像;其次,由热图像得到人体掩模图像,进而在ORB-SLAM2系统框架下构建静态特征提取与数据关联策略,实现基于三模图像的视觉里程计;然后,基于人体掩模图像更新深度图像,滤除人体区域,进而完成基于三模图像的静态环境稠密地图构建;最后,在室内动态场景下进行实验验证,结果表明所提出算法在室内动态场景下可有效剔除动态对象的干扰特征,相对传统SLAM算法具有明显优势。
基金supported by the National Natural Science Foundation of China(Grant Nos.61425008,61333004 and 61273054)Top-Notch Young Talents Program of China,and Aeronautical Foundation of China(Grant No.20135851042)
文摘As one of the major contributions of biology to competitive decision making, evolutionary game theory provides a useful tool for studying the evolution of cooperation. To achieve the optimal solution for unmanned aerial vehicles （UAVs） that are car- rying out a sensing task, this paper presents a Markov decision evolutionary game （MDEG） based learning algorithm. Each in- dividual in the algorithm follows a Markov decision strategy to maximize its payoff against the well known Tit-for-Tat strate- gy. Simulation results demonstrate that the MDEG theory based approach effectively improves the collective payoff of the roam. The proposed algorithm can not only obtain the best action sequence but also a sub-optimal Markov policy that is inde- pendent of the game duration. Furthermore, the paper also studies the emergence of cooperation in the evolution of self-regarded UAVs. The results show that it is the adaptive ability of the MDEG based approach as well as the perfect balance between revenge and forgiveness of the Tit-for-Tat strategy that the emergence of cooperation should be attributed to.
