天然气输送支干线生产管理探讨

天然气输送管线安全运行面临风险,本文主要对天然气输送管线生产管理进行探讨。     

Random mechanisms for house allocation with existing tenants

We study the house allocation problem with existing tenants: $n$ houses (stand for “indivisible objects”) are to be allocated to $n$ agents; each agent needs exactly one house and has strict preferences; $k$ houses are initially unowned; $k$ agents initially do not own houses; the remaining $n-k$ agents (the so-called “existing tenants”) initially own the remaining $n-k$ houses (each owns one). In this setting, we consider various randomized allocation rules under which voluntary participation of existing tenants is assured and the randomization procedure either treats agents equally or discriminates against some (or all) of the existing tenants. We obtain two equivalence results, which generalize the equivalence results in Abdulkadiroğlu and Sönmez (1999) and Sönmez and Ünver (2005).     

Stabilizing and destabilizing mechanisms: A new perspective to understand business cycles

Economists believe that economic fluctuations can be smoothed by stabilization mechanisms, such as price adjustment, embedded in the economy. While price adjustment can be seen as a stabilization mechanism, are there mechanisms that can destabilize an economy? We find that as early as 1939, Harrod discussed a destabilization mechanism, the firm's investment adjustment, illustrated in his knife-edge puzzle. We build a macro-dynamic model with investment and price as the core macroeconomic variables. Our analysis shows that the interaction between the stabilization mechanism (price adjustment) and the destabilization mechanism (investment adjustment) generates fluctuations and cycles. However, due to price stickiness, the price adjustment mechanism may not be enough to stabilize the economy. In this case, a government stabilization policy is necessary for further stabilization. As this paper also addresses the microfoundations of Keynesian quantity theory, including the choice of output and investment in optimization, it can be related to traditional Keynesian economics, with a new perspective to understand business cycles.     

Cooperative game analysis of coordination mechanisms under fairness concerns of a green retailer

This study discusses how a green retailer's fairness concerns affect product greenness and profit and explores how to distribute surplus profits under the fairness concerns using cooperative game theory. Research findings indicate that cooperation contributes to increasing channel profits and improving product greenness, but the fairness concerns are detrimental to them. The three proposed coordination mechanisms (SVM, NSM, and TVM) are feasible to ensure coalition stability, but their beneficiaries differ. NSM benefits a manufacturer, while SVM benefits retailers. Additionally, the green retailer's fairness concerns serve as distribution tools to narrow profit gaps between the manufacturer and the green retailer.     

治理机制对顾客参与价值共创行为的影响——虚拟品牌社区的实证研究

虚拟品牌社区是企业与顾客进行价值共创的重要平台,顾客参与价值共创行为对企业长远发展具有十分重要的作用。现有研究多是基于不同的理论从顾客视角出发探索顾客参与价值共创行为受到的心理动机和个人特征等因素的影响,鲜有从企业视角出发,探索治理机制对虚拟品牌社区中顾客参与价值共创行为的影响。本文立足交易成本理论与社会交换理论,从企业视角切入,引入关系质量作为中介变量,构建虚拟品牌社区治理机制、关系质量与顾客参与价值共创行为的关系整合模型。采用问卷调查法对模型进行验证,研究结果显示:(1)契约治理机制只对知识贡献行为产生显著正向影响,对顾客公民行为的影响不显著,而关系治理机制对知识贡献行为与顾客公民行为均具有显著正向影响。(2)关系质量在契约治理机制与顾客公民行为的关系中起完全中介作用,在契约治理机制与知识贡献行为、关系治理机制与知识贡献行为以及关系治理机制与顾客公民行为的关系中起部分中介作用。由研究结论可知,虚拟品牌社区一方面应综合运用契约治理机制与关系治理机制来有效地促进顾客参与价值共创行为,以弥补单独运用某一种治理机制存在的不足;另一方面也应注重关系质量在虚拟品牌社区中促进顾客参与价值共创行为的重要作用。这些研究发现为促进虚拟品牌社区的可持续发展提供了有价值的启示。     

试论国家加大工程质量整治行动

调动全社会各部门、各级领导高度重视工程质量的整治行动,抓住建筑市场混乱的源头和要害,还建筑业一个健康、规范、有序的建筑市场新秩序。     

Forecasting the Covid-19 recession and recovery: Lessons from the financial crisis

We consider simple methods to improve the growth nowcasts and forecasts obtained by mixed-frequency MIDAS and UMIDAS models with a variety of indicators during the Covid-19 crisis and recovery period, such as combining forecasts across various specifications for the same model and/or across different models, extending the model specification by adding MA terms, enhancing the estimation method by taking a similarity approach, and adjusting the forecasts to put them back on track using a specific form of intercept correction. Among these methods, adjusting the original nowcasts and forecasts by an amount similar to the nowcast and forecast errors made during the financial crisis and subsequent recovery seems to produce the best results for the US, notwithstanding the different source and characteristics of the financial crisis. In particular, the adjusted growth nowcasts for 2020Q1 get closer to the actual value, and the adjusted forecasts based on alternative indicators become much more similar, all unfortunately indicating a much slower recovery than without adjustment, and very persistent negative effects on trend growth. Similar findings also emerge for forecasts by institutions, for survey forecasts, and for the other G7 countries.     

A number‐of‐modes reference rule for density estimation under multimodality

We consider kernel density estimation for univariate distributions. The question of interest is as follows: given that the data analyst has some background knowledge on the modality of the data (for instance, ‘data of this type are usually bimodal’), what is the adequate bandwidth to choose? We answer this question by extending Silverman's idea of ‘normal‐reference’ to that of ‘reference to a Gaussian mixture’. The concept is illustrated in the light of real data examples.     

TEM4之作文错误分析及其对教学的反拨作用

学生写作中经常出现词汇、语法、措辞等方面的错误,教师在教学中应分析其错误形成的原因,正确对待其错误,努力改进教学方法和评价手段,鼓励学生自主学习,以提高学生文化修养和作文质量。     

错误分析理论在高校英语听力课中的应用

错误分析是二语习得研究的重要内容,是了解学习者所掌握知识的重要信息来源.从错误分类入手,对英语学习者听力理解过程中的主要障碍进行测试并进行错误分析,在教学中设法提高学生的语音和语感,在课堂训练中抓住重点信息,有助于提高学生的听力理解能力.