中国A股市场新股抑价现象的实证研究

首先定义了新股抑价水平,提出了影响抑价水平的可能因素,在此基础上确定了基本抑价模型、非受限抑价模型、受限抑价模型和对数抑价模型;随后描述了中国A股市场的新股抑价现象,并给出了各抑价模型实证研究结果;最后比较了四个模型在预测新股上市价格方面的优劣性.     

基于Petri网的微博网络信息传播模型

微博网络中的信息传播模型是分析用户行为,找出传播路径,确定领袖人物,发现舆情热点等研究的基础。虽然多种不同角度的信息传播模型已经得到广泛研究,但缺乏对信息动态传播过程的直观描述。本文基于Petri网的结构和特征,针对微博网络信息传播过程,提出了一种简单直观的描述模型,该模型首先对微博网络的信息动态传播过程中的对象进行结构化描述。本文根据微博网络的用户结构关系,并利用Petri网的相关理论,形式化解释和定义信息传播基本对象,从而更加直接描述了微博网络中的转发、评论、回复等多种用户行为。在此基础上,本文利用Petri网能够描述信息流动问题的特征,结合颜色Petri网和时延Petri网,从Petri网系统的角度表示信息动态传播路径,并研究网络的动态性质和传播条件,使得信息传播模型更加真实地模拟信息传播情况。最后本文分析信息传播算例和新浪微博真实数据实验,验证了模型的有效性和可行性,为舆情态势分析以及用户行为的研究提供帮助和支持,同时也为其它社交网络信息传播的用户行为描述提供了新的思路。     

网络群体事件政府治理的演化博弈分析

利用演化博弈模型预测舆论的发展趋势,对政府应对网络群体事件采取的治理模式进行了研究.在一般化复制动态模型基础上建立网络群体事件舆论的传播方程,将地方政府部门与弱势群体的策略互动和行为演化融入到传染病传播模型中,用以模拟舆论的扩散和收敛过程.结果表明:在网络群体事件初期,如果弱势群体通过抗争获得政府补偿的概率不断增大,将造成事态的扩大.此时,地方政府应控制信息的交流程度与初始抗争人数,减缓舆论的扩散;在网络群体事件舆论大范围扩散阶段,上级政府介入并采取惩罚措施,及时披露信息,促使网络舆论的收敛平息,实现社会福利最大化.     

考虑自适应行为的研发网络风险传播模型构建及仿真

构建风险视域下研发网络企业自适应行为规则，基于SIS模型构建研发网络风险传播模型，运用数值仿真的方法通过改变模型参数探索在考虑自适应行为的情况下研发网络的风险传播规律，研究结果表明：（1）C1策略增强了网络的层次性和社团强度，一定程度上抑制了研发网络中风险的传播；C2策略下节点之间新连接的建立更多是基于临近性的考量，容易陷入路径依赖和能力陷阱；（2）研发网络企业的自适应行为会导致社团强度的涨落，平均路径长度的下降以及平均聚类系数的增长充分体现出C1策略的有效性。（3）C1策略下，断边概率p与I*之间呈现"U"型相关关系；在C2策略下随着断边概率p的增长I*逐渐降低。（4）在C1策略和C2策略下，随着参数ζ的增长I*也随之增长，可知组织依赖水平是研发网络风险传播控制中需要重点关注的因素。本文揭示了在考虑自适应行为的情况下研发网络的风险传播规律，为网络化运作背景下研发网络治理提供理论依据。     

基于随机Petri网的突发事件信息演化模型

突发事件爆发后通常会引发事件信息的演化现象，而信息演化可能导致的负面舆情危机严重影响社会生活秩序，如何准确把握突发事件信息的演化规律是社会发展新形势下公共事务风险治理的重要内容。首先采用案例分析和结构化描述方法提取突发事件信息演化现象的内外部属性，并提出其演化系统。进而，构建该系统的随机Petri网模型及其同构的马尔可夫链。最后，通过情景仿真研究系统的均衡状态变动规律及其调控问题。研究过程中，提出突发事件信息演化现象的结构化描述、演化系统及不同演化状态，得出系统均衡状态变动规律及其调控机制。在此基础上，指出未来应考虑带有碰撞和耦合机制的多种信息演化规律及其调控问题。     

全球性公共卫生危机治理:趋势与重点北大核心CSCDCSSCI

全球性公共卫生危机源于突发的全球重大公共卫生事件,不确定性和复杂性特征突出,对世界经济与社会发展具有长期影响,应对这一危机则是跨时域、跨地域、跨领域的一项系统工程.揭示全球性公共卫生危机的形成机理、演化规律、治理策略,探究相应的危机预防与处置方法、多元主体的合作网络构建方式、危机联防联控措施与应对标准规范等内容,具有重要理论意义和应用价值.现有研究已在构建整体性应急治理体系、增强政府危机决策能力、促进多元主体协调共治及技术赋能公共卫生危机治理等方面实现了一定的知识积累.未来,中国管理科学应继续围绕全球性公共卫生危机的影响因素、形成机理及演化规律,应急资源供应与分配管理,多元主体参与机制及其行为规律,后危机时代的企业管理以及加强国际传播能力建设等问题展开学术探索.     

城市管理的智能化转型：研究框架与展望

全球性公共卫生危机源于突发的全球重大公共卫生事件,不确定性和复杂性特征突出,对世界经济与社会发展具有长期影响,应对这一危机则是跨时域、跨地域、跨领域的一项系统工程.揭示全球性公共卫生危机的形成机理、演化规律、治理策略,探究相应的危机预防与处置方法、多元主体的合作网络构建方式、危机联防联控措施与应对标准规范等内容,具有重要理论意义和应用价值.现有研究已在构建整体性应急治理体系、增强政府危机决策能力、促进多元主体协调共治及技术赋能公共卫生危机治理等方面实现了一定的知识积累.未来,中国管理科学应继续围绕全球性公共卫生危机的影响因素、形成机理及演化规律,应急资源供应与分配管理,多元主体参与机制及其行为规律,后危机时代的企业管理以及加强国际传播能力建设等问题展开学术探索.     

企业内部知识传播的系统动力学模型研究

在企业中知识只有被员工传播和使用才能充分体现它的价值.探讨企业内部知识传播产生的基础,提出知识势能的概念,并用其衡量个体所拥有的某一特定领域知识的量的大小;分析知识在企业内部得以传播的动力,并对传播过程中涉及到的因素进行划分和描述,进而提出企业内部的知识传播概念模型;此外,引入系统动力学的相关概念和理论,对企业内部的知识传播进行量化模型构建,提出3个量化模型.模型描述了知识在经过传播后被知识接收者接受的过程中知识接收者的知识势能变化过程,结果发现知识接收者的知识势能变化曲线主要是由S型增长曲线构成,S型增长曲线可以被划分为3个阶段,并且影响每个阶段曲线的主要因素不同,因此企业可以通过适当调整一些因素得到所期望的知识接收者的知识势能曲线.     

智慧健康医疗管理研究热点分析

全球性公共卫生危机源于突发的全球重大公共卫生事件,不确定性和复杂性特征突出,对世界经济与社会发展具有长期影响,应对这一危机则是跨时域、跨地域、跨领域的一项系统工程.揭示全球性公共卫生危机的形成机理、演化规律、治理策略,探究相应的危机预防与处置方法、多元主体的合作网络构建方式、危机联防联控措施与应对标准规范等内容,具有重要理论意义和应用价值.现有研究已在构建整体性应急治理体系、增强政府危机决策能力、促进多元主体协调共治及技术赋能公共卫生危机治理等方面实现了一定的知识积累.未来,中国管理科学应继续围绕全球性公共卫生危机的影响因素、形成机理及演化规律,应急资源供应与分配管理,多元主体参与机制及其行为规律,后危机时代的企业管理以及加强国际传播能力建设等问题展开学术探索.     

企业通过联盟进行隐性知识转移的三阶段模型

本文针对隐性知识的特征及知识在联盟中转移的过程和特点,建立了企业通过联盟进行隐性知识转移的微分动力学模型,在此基础上,进一步分析了影响联盟隐性知识转移的渐近解的主要参数控制.模型揭示了联盟中隐性知识转移的规律,指出了企业获得联盟中隐性知识的条件及隐性知识在联盟企业中传播的条件,同时也阐明了一些能改进隐性知识转移效果的途径,文中最后还分析了模型对联盟中知识管理的现实意义.     

Simulation of a police patrol activity

This paper describes the use of the Patrol Car Allocation Model to structure the relationships which exist between the utilization of patrol resources and various measures of performance. The relationships depict the cost vs service trade-offs that are present in patrol allocation decisions. The results of an actual study are presented along with a discussion of their potential value to the police patrol allocation function.     

Supporting Quick Response Through Scheduling of Make-to-Stock Production/Inventory Systems*

Scheduling of traditional job shops in make-to-order systems has seen extensive research over the past three decades. In such systems, performance is often related to various job completion metrics such as average flow time, average lateness, etc. This paper examines a scheduling problem in a make-to-stock environment where individual job completion measures are irrelevant. In this case, customer orders are satisfied through on-hand inventory where customer service is more closely related to the manufacturer's ability to quickly satisfy demand. We consider the role of scheduling in reducing inventories and improving customer service in the context of a manufacturer who assembles several different products on a single assembly line. We develop scheduling rules for such a system and experimentally compare their performance to those typically used in such environments. Our results indicate that rules which consider the inventory position and demand forecast outperform traditional fixed cycle rules.     

Preference Monotonicity and Information Aggregation in Elections

If voter preferences depend on a noisy state variable, under what conditions do large elections deliver outcomes “as if” the state were common knowledge? While the existing literature models elections using the jury metaphor where a change in information regarding the state induces all voters to switch in favor of only one alternative, we allow for more general preferences where a change in information can induce a switch in favor of either alternative. We show that information is aggregated for any voting rule if, for a randomly chosen voter, the probability of switching in favor of one alternative is strictly greater than the probability of switching away from that alternative for any given change in belief over states. If the preference distribution violates this condition, there exist equilibria that produce outcomes different from the full information outcome with high probability for large classes of voting rules. In other words, unless preferences closely conform to the jury metaphor, information aggregation is not guaranteed to obtain.     

Priority dispatching rules in job shops with assembly operations and random delays

The article reports the results of an experimental investigation into priority dispatching rules for a job shop with assembly operations. A job is made up of several parts, where parts are individual entities requiring several operations in different machine centres. The study was directed towards rules which attempt to co-ordinate the completion time of parts required in the same job. This mainly involves rules that utilise job status information such as operation float, number of parts completed, and number of operations remaining on each part. Results indicate that job status information improves most of the measures of performance used.     

When Precaution Creates Misunderstandings: The Unintended Effects of Precautionary Information on Perceived Risks,the EMF Case

In the past decade, growing public concern about novel technologies with uncertain potential long‐term impacts on the environment and human health has moved risk policies toward a more precautionary approach. Focusing on mobile telephony, the effects of precautionary information on risk perception were analyzed. A pooled multinational experimental study based on a 5 × 2 × 2 factorial design was conducted in nine countries. The first factor refers to whether or not information on different types of precautionary measures was present, the second factor to the framing of the precautionary information, and the third factor to the order in which cell phones and base stations were rated by the study participants. The data analysis on the country level indicates different effects. The main hypothesis that informing about precautionary measures results in increased risk perceptions found only partial support in the data. The effects are weaker, both in terms of the effect size and the frequency of significant effects, across the various precautionary information formats used in the experiment. Nevertheless, our findings do not support the assumption that informing people about implemented precautionary measures will decrease public concerns.     

Risk Management of Domino Effects Considering Dynamic Consequence Analysis

Domino effects are low‐probability high‐consequence accidents causing severe damage to humans, process plants, and the environment. Because domino effects affect large areas and are difficult to control, preventive safety measures have been given priority over mitigative measures. As a result, safety distances and safety inventories have been used as preventive safety measures to reduce the escalation probability of domino effects. However, these safety measures are usually designed considering static accident scenarios. In this study, we show that compared to a static worst‐case accident analysis, a dynamic consequence analysis provides a more rational approach for risk assessment and management of domino effects. This study also presents the application of Bayesian networks and conflict analysis to risk‐based allocation of chemical inventories to minimize the consequences and thus to reduce the escalation probability. It emphasizes the risk management of chemical inventories as an inherent safety measure, particularly in existing process plants where the applicability of other safety measures such as safety distances is limited.     

External costs: Myth or rationale for state intervention?

The paper considers the extent to which problems of environmental pollution can be left to the market system. The concept of external cost is used to establish the presumption that market forces will lead to excessive pollution. The performance criterion, that of Pareto efficiency, leading to this presumption is discussed. It is shown that for significant problems of pollution it is not possible to limit the role of the state to that of re-defining property rights. What is necessary is state intervention by way of the taxing, or regulation, of discharges into the environment: where external effects are undepletable, markets cannot meet the requirements of Pareto efficiency. Government intervention to meet such requirements requires that the government has information which is, in practice, either unavailable or very costly. Intervention towards more restricted goals is discussed. It is shown that arguments to the effect that the role of the state can be restricted to defining private property rights are based on assumptions which are irrelevant to significant problems. In particular, it is argued that a recent publication by the Institute of Economic Affairs does not, as claimed, show either that external costs do not exist, or that they exist but imply a minor role for the state in the protection of the natural environment.     

HEURISTIC LOT-SIZING AND SEQUENCING RULES IN A MULTISTAGE PRODUCTION-INVENTORY SYSTEM

Material Requirements Planning (MRP) is currently being applied and used extensively in industry and is being proclaimed as the solution to many of the problems of traditional production-inventory control problems. While the latter may be true, MRP is not without its own problems, two of which are the decisions concerning the appropriate lotsizing and sequencing rules to use in order to improve system performance. This paper describes a computer simulation study which was conducted to determine the effects of using various sequencing and lot-sizing rules on various performance criteria in a multistage, multiproduct, production-inventory system using MRP. The results of the study indicate that the application of various rules causes changes in system performance and that an interaction effect exists between lot-sizing and sequencing rules. What is more important is that a set of guidelines is developed to enable the practitioner to choose a lot-sizing rule and a sequencing rule that will tend to improve the performance of his system for the various performance criteria.     

双层社交网络上的企业舆情 传播模型及控制策略研究

  随着社会化媒体时代的到来,社交网络中企业舆情的形成与传播为现代企业管理带来了深远影响。当前关于企业舆情传播的研究主要以在线社交网络为传播媒介展开,鲜有研究考虑舆情在传统线下网络与在线社交网络的同时传播。此外,通过识别社交网络中最具有影响力的权威节点以实现信息传播规模最大化是当前信息传播控制策略的主要思路,而基于价值共创理论针对最小化负面舆情传播范围的控制策略相对较少。         基于此,探索双层社交网络上的企业舆情传播规律和控制策略。考虑到线上、线下活动的相互依赖性,基于复杂网络理论和传播动力学等方法,构建双层社交网络上的舆情传播模型;对传播模型进行仿真实验,并将仿真结果与单层社交网络进行对比;基于价值共创理论提出以减缓未知者向已知者转化为目的和以加速传播者向免疫者转化为目的的两类企业舆情传播的控制策略,并利用仿真实验验证控制策略的有效性。         研究结果表明,①在双层社交网络中,舆情的传播同时具备线上网络和线下网络中的传播特征;②双层社交网络层间的耦合连接模式对舆情的传播过程具有显著影响,同配连接最利于舆情的传播,而异配连接最不利于舆情的扩散;③企业的第1类和第2类舆情控制策略对舆情传播的抑制效果具有阶段性,即两类控制策略在舆情传播初期边际效用最大,资源投入越多,舆情传播的抑制效果越明显;而在传播后期,控制策略的边际效用趋近于0,无法实现预期效果。         现代企业在网络舆情管理过程中,除利用正面舆情树立企业形象外,也应时刻关注负面舆情对企业发展带来的消极影响。为有效地规避负面舆情传播对企业带来的损失,企业可通过在社交网络中投入资源,如实施广告宣传、经济赔偿等价值共创策略来抑制舆情的传播,但需要注意控制策略及实施控制时间点的选择。研究结论为企业正确应对网络舆情、保持竞争优势等方面提供了重要依据。     

碳税制度下企业产品升级及信息披露策略研究

在实行碳税制度的背景下,本文构建了包含两家制造商的双寡头模型,以其中一家制造商是否投资产品升级减排作为关键信息,分别研究信息不公开(模型1)和信息公开(模型2)时两家制造商的均衡定价与最优利润以及制造商产品升级的条件,并且进一步研究当制造商同时掌握技术决策权和信息披露权时选择四种不同决策方案的条件。理论结果表明,如果升级后单位实际生产成本变大,制造商选择不升级且不公开;如果升级后单位实际成本变小,当升级后利润增值大于固定成本投入时,制造商选择升级并不公开,反之,选择不升级并公开。无论升级前后单位实际成本大小关系如何,制造商都不会选择升级且公开信息。数值试验部分表明,当制造商同时掌握技术选择权和信息披露权时,碳税是驱动制造商进行升级减排的主要因素,随着碳税的提高,制造商会依次从不升级不公开,不升级公开到升级不公开做决策。当不升级的概率越大时,制造商会在较低的碳税点越早开始升级;当减排努力越大时,制造商会在较高的碳税点才开始升级。