民营上市公司集团治理与终极控制人侵占效应分析

本文以民营上市公司为样本,采用2002-2004年的面板数据,针对民营上市公司中普遍存在的集团治理现象,理论分析并实证检验了集团治理的各因素对终极控制人行为的综合影响.研究发现,在集团治理条件下,随着控制权和现金流权偏离程度的增加,终极控制人采取具有侵占效应的行为的激励越强.而上市公司的治理结构能够对这一影响起到调节作用,其中,股权结构中的内部股东集团比例增加会强化侵占效应的激励;董事会结构中外部董事比例的增加会抑制终极控制人的侵占效应行为.本文的经验证据表明,在对民营上市公司集团治理结构加强监管的同时,正确认识外部董事的作用、强化董事会的独立性并完善内部机制能够取到良好的治理效果.     

Minimum number of disjoint linear forests covering a planar graph

Graph coloring has interesting real-life applications in optimization, computer science and network design, such as file transferring in a computer network, computation of Hessians matrix and so on. In this paper, we consider one important coloring, linear arboricity, which is an improper edge coloring. Moreover, we study linear arboricity on planar graphs with maximum degree \(\varDelta \ge 7\) . We have proved that the linear arboricity of \(G\) is \(\lceil \frac{\varDelta }{2}\rceil \) , if for each vertex \(v\in V(G)\) , there are two integers \(i_v,j_v\in \{3,4,5,6,7,8\}\) such that any two cycles of length \(i_v\) and \(j_v\) , which contain \(v\) , are not adjacent. Clearly, if \(i_v=i, j_v=j\) for each vertex \(v\in V(G)\) , then we can easily get one corollary: for two fixed integers \(i,j\in \{3,4,5,6,7,8\}\) , if there is no adjacent cycles with length \(i\) and \(j\) in \(G\) , then the linear arboricity of \(G\) is \(\lceil \frac{\varDelta }{2}\rceil \) .     

An individual-based model of information diffusion combining friends’ influence

In many real-world scenarios, an individual accepts a new piece of information based on her intrinsic interest as well as friends’ influence. However, in most of the previous works, the factor of individual’s interest does not receive great attention from researchers. Here, we propose a new model which attaches importance to individual’s interest including friends’ influence. We formulate the problem of maximizing the acceptance of information (MAI) as: launch a seed set of acceptors to trigger a cascade such that the number of final acceptors under a time constraint T in a social network is maximized. We then prove that MAI is NP-hard, and for time \(T = 1,2\) , the objective function for information acceptance is sub-modular when the function for friends’ influence is sub-linear in the number of friends who have accepted the information (referred to as active friends). Therefore, an approximation ratio \((1-\frac{1}{e})\) for MAI problem is guaranteed by the greedy algorithm. Moreover, we also prove that when the function for friends’ influence is not sub-linear in the number of active friends, the objective function is not sub-modular.     

Parameterized algorithms for min–max 2-cluster editing

For a given graph and an integer t, the Min–Max 2-Clustering problem asks if there exists a modification of a given graph into two maximal disjoint cliques by inserting or deleting edges such that the number of the editing edges incident to each vertex is at most t. It has been shown that the problem can be solved in polynomial time for \(t<n/4\), where n is the number of vertices. In this paper, we design parameterized algorithms for different ranges of t. Let \(k=t-n/4\). We show that the problem is polynomial-time solvable when roughly \(k<\sqrt{n/32}\). When \(k\in o(n)\), we design a randomized and a deterministic algorithm with sub-exponential time parameterized complexity, i.e., the problem is in SUBEPT. We also show that the problem can be solved in \(O({2}^{n/r}\cdot n^2)\) time for \(k<n/12\) and in \(O(n^2\cdot 2^{3n/4+k})\) time for \(n/12\le k< n/4\), where \(r=2+\lfloor (n/4-3k-2)/(2k+1) \rfloor \ge 2\).     

Three‐Stage Decision‐Making Model under Restricted Conditions for Emergency Response to Ships Not under Control

A ship that is not under control (NUC) is a typical incident that poses serious problems when in confined waters close to shore. The emergency response to NUC ships is to select the best risk control options, which is a challenge in restricted conditions (e.g., time limitation, resource constraint, and information asymmetry), particularly in inland waterway transportation. To enable a quick and effective response, this article develops a three‐stage decision‐making framework for NUC ship handling. The core of this method is (1) to propose feasible options for each involved entity (e.g., maritime safety administration, NUC ship, and ships passing by) under resource constraint in the first stage, (2) to select the most feasible options by comparing the similarity of the new case and existing cases in the second stage, and (3) to make decisions considering the cooperation between the involved organizations by using a developed Bayesian network in the third stage. Consequently, this work provides a useful tool to achieve well‐organized management of NUC ships.     

关于中国消费者分群范式(China-Vals)的研究

本文以中国消费者的生活形态研究为中心,借鉴西方研究成果,就消费者的分群、价值观、生活形态及社会分层等市场细分相关理论进行了深入探索,构建了中国独特的系统范式,提出了五项新的理论性观点,即中国消费者14大族群、七点文化元素、中国社会心理结构的三层结论(安全\认同\事业)、China-Vals模型和应用性价值观。     

技能型合作的学习能力对合作绩效的影响

本文在综合研究国内外企业合作战略的基础上,使用聚类分析法,对152个合作企业的数据进行分析.本文对技能型合作企业强调学习能力的不同方面,对企业进行分类.分成强调学习能力的能力全面型、知识应用型、努力学习型和能力起步型等类别的技能合作型企业.四种类型企业的合作绩效,其成本、规模、学习效果等效应,要好于经营业绩、竞争优势及技术创新等效应.     

委托-代理中代理人过度自信水平衰减速度模型

利用Bayes法则建立数学模型研究委托-代理关系中代理人过度自信水平的衰减速度问题.研究结果表明,如果代理人开始时是过度自信的,那么从平均来说,代理人的过度自信水平将长期存在并随着时间的推移而递减.而且代理人过度自信水平的衰减速度与其过度自信水平本身的高低有关,当伐理人的过度自信水平很高或很低时,代理人向着理性收敛的速度接近于0;而当代理人的过度自信水平从0上升到最大可能值时,代理人向着理性的收敛速度将先增加、后减小,并在其间的某个中间值达到最大.但这只是代理人过度自信水平的一种总体的平均变化趋势,在实际应用中,代理人的过度自信水平将呈现出波动下降趋势.     

Broadcast Routing with Minimum Wavelength Conversion in WDM Optical Networks

We consider dynamic routing of broadcast connections in WDM optical networks. Given the current network state, we want to find a minimum set of network nodes S such that a broadcast routing using only the nodes in S as wavelength conversion nodes can be found. This ensures that the average conversion delay from the source to all destinations is minimized. We refer to the problem as Broadcast Conversion Node Selection (BCNS) problem. We prove that BCNS has no polynomial-time approximation with performance ratio ln n for < 1 unless NPDTIME(n^{O(log log n)}) where n is the number of vertices in the input graph. We present a greedy approximation algorithm for BCNS that achieves approximation ratio 2+ln n. Simulation results show that the algorithm performs very well in practice, obtaining optimal solutions in most of the cases.     

Evaluating Weight of Evidence in the Mystery of Balkan Endemic Nephropathy

Balkan endemic nephropathy (BEN) is a chronic, progressive wasting disease of the kidneys, endemic in certain rural regions of the Balkan nations Croatia, Serbia, Bulgaria, and Romania. It is irreversible and ultimately fatal. Though this disease was first described in the 1950s, its causes have been a mystery and a source of much academic and clinical contention. Possible etiologic agents that have been explored include exposure to metals and metalloids, viruses and bacteria, and the dietary toxins aristolochic acid (AA) and ochratoxin A (OTA). AA is a toxin produced by weeds of the genus Aristolochia, common in Balkan wheat fields. Aristolochia seeds may intermingle with harvested grains and thus inadvertently enter human diets. OTA is a mycotoxin (fungal toxin) common in many foods, including cereal grains. In this study, we analyzed the weight of evidence for each of the suspected causes of BEN using the Bradford Hill criteria (BHC): nine conditions that determine weight of evidence for a causal relationship between an agent and a disease. Each agent postulated to cause BEN was evaluated using the nine criteria, and for each criterion was given a rating based on the strength of the association between exposure to the substance and BEN. From the overall available scientific evidence for each of these suspected risk factors, AA is the agent with the greatest weight of evidence in causing BEN. We describe other methods for testing causality from epidemiological studies, which support this conclusion of AA causing BEN.