How social media matter: Repression and the diffusion of the Occupy Wall Street movement

This study explores the role played by social media in reshaping the repression-mobilization relationship. Drawing on the case of the Occupy Wall Street movement, we examine the impact of Facebook and Twitter on the spatial diffusion of protests during a period of heightened state repression. Results from event history analyses suggest that the effects of repression on protest diffusion are contingent on the presence of social media accounts supporting the movement. We find that state repression at earlier protest sites encouraged activists to create Facebook and Twitter accounts in their own cities, which then served as important vehicles for the initiation of new Occupy protests. Moreover, results suggest that repression incidents can directly facilitate future protests in cities that already have Occupy Facebook accounts. This study highlights the potential of social media to both mediate and moderate the influence of repression on the diffusion of contemporary movements.     

二维Lotka-Volterra竞争扩散系统的渐近传播速度

通过上下解方法及比较原理,得到了二维扩散Lotka-Volterra竞争系统的渐近传播速度.     

重大公共危机网络舆情扩散监测和规律分析

网络传播技术手段裂变式发展,互联网正在形成舆论的＂自由市场＂,因此,对重大突发公共事件网络舆情扩散规律进行识别和引导的重要性日益突现。基于复杂系统网络信息传播与扩散的＂六度分隔＂假说、小世界网络和无尺度网络等社会网络理论,分析了重大突发公共危机网络舆情信息扩散演化过程,建立了基于主体（Agent）的网络舆情扩散监测模型以及网络舆情扩散规律分析模型。仿真结果得出的网络舆情扩散规律符合实际情况。该研究对于化解社会矛盾、有效解决公共危机以及构建和谐社会等具有重要的学术价值和深远的社会意义。     

Changes in Product Attributes and Costs as Drivers of New Product Diffusion and Substitution

Diffusion theory has typically focused on how communication, internal or external to a social system, leads to adoptions and diffusion of an innovation. We develop a diffusion and substitution model based on a somewhat different perspective. In some cases, progressive improvements in product attributes and/or continual cost reduction seem to be a key driver of the diffusion process. For example, after introduction of the 5.25‐inch disk drive, its capacity continually increased, and accordingly, so did customer willingness‐to‐pay. Our model is based on a linear reservation price framework, in which a product is described by its depth (defined as the difference between a product̂s maximum reservation price and its production cost), and its breadth (related to the slope of its reservation price curve), indicating how broadly it appeals across various customer segments. Because of changes in product depths and breadths over time, customers who previously preferred the old product may later prefer the new product, thus creating the diffusion process. While the Bass model describes diffusion as a function of the coefficients of innovation and imitation, in our model, it is described by the coefficients of depth and breadth (the rates of change in relative depth and breadth), along with an S‐coefficient that we associate with the technology S‐curve. We fit our model to data from the disk‐drive and the microprocessor industries.     

Nadaraya–Watson estimator for I.I.D. paths of diffusion processes

This paper deals with a nonparametric Nadaraya–Watson (NW) estimator of the drift function computed from independent continuous observations of a diffusion process. Risk bounds on the estimator and its discrete-time approximation are established. The paper also deals with extensions of the PCO and leave-one-out cross-validation bandwidth selection methods for our NW estimator. Finally, some numerical experiments are provided.     

College Women's Gynecological Health Care Practices and Preferences

Abstract

Panic disorder is characterized by recurrent, sudden, often unprovoked attacks of intense, diffuse autonomic discharge accompanied by severe anxiety as distinguished from ordinary generalized anxiety. Recent research indicates a biochemical abnormality that predisposes some individuals to the disorder, which generally begins in young adulthood and affects women twice as frequently as men. Untreated panic disorder follows a chronic, fluctuating course. Complications include hypochondriasis, anticipatory anxiety, phobic avoidance and agoraphobia, abuse of alcohol and sedative drugs, and depression.

Diagnosis is complicated by patients' complaints of physical rather than emotional symptoms. Workups can be avoided if the physician considers the diagnosis in apparently healthy young adults who present with episodic cardiac, gastrointestinal, neurologic, and/or respiratory symptoms. The physician needs to be able to distinguish the symptoms of panic disorder from those of ordinary anxiety and also to rule out medical conditions that mimic panic disorder.

Neither conventional benzodiazepines nor psychotherapy alone is very effective in stopping panic attacks, but alprazolam, imipramine, and phenelzine are all highly effective. Alprazolam has fewer troublesome side effects, but patience and perseverance are necessary to reach therapeutic levels with all three drugs. Inadequate dosage is the most common cause of treatment failure. Most patients do well once their attacks are controlled and do not require close follow-up. Patient education is an important part of long-term management because relapses are common.     

气象灾害事件正式信息扩散模型研究

对气象灾害事件信息的研究是解构气象灾害事件的重要路径。依据信息传播的渠道和主体,可以将气象灾害事件信息划分为正式信息和非正式信息。气象灾害事件正式信息的扩散路径相对固定,发布具有可控性,但是正式传播渠道不能保证其真实性。气象灾害正式信息在扩散过程中具有非线性、稀释性和支离性等特征。在此基础上构建的气象灾害事件正式信息扩散模型表明,对气象灾害信息持开放态度,注重信息扩散方式的创新,加强对专业性信息的通俗化处理,重视对公众的培训和教育以及选择合适的气象灾害信息发布策略,将有助于引导信息扩散,优化气象灾害事件的应急处置。     

Child Welfare Workers' Adoption of Decision Support Technology

Child welfare workers must process complex information in deciding to refer clients to appropriate mental health services. Decision support systems have been demonstrated in other fields to be an important tool, yet little research has been done in child welfare. This study focused on the adoption of a specific decision support system into child welfare practice. Quantitative analysis was used to demonstrate the diffusion of innovation process among a sample of state child welfare workers, while qualitative analysis was used to explain the facilitators and barriers to decision support systems adoption. Results indicate that for decision support systems to be widely adopted in child welfare practice, they should be integrated into the referral system and include workers' knowledge and experiences with referral resources. For successful adoption, decision support systems need to respect the natural logic and flow of worker interaction as well as organizational constraints.     

The Policy Transfer Model

ABSTRACT

“New” social welfare policies are often actually policies borrowed from other states or nations. This paper reviews the recent theoretical developments in understanding the processes of policy transfer and presents a “policy transfer” model that can be a useful heuristic tool for social workers engaged in policy making. It discusses how the field of social work can benefit from understanding the factors underlying successful and unsuccessful policy transfer, and argues for the inclusion of the study of policy transfer in social welfare policy courses.     

A Sales Forecast Model for Short‐Life‐Cycle Products: New Releases at Blockbuster

We develop, in this article, a sales model for movie and game products at Blockbuster. The model assumes that there are three sales components: the first is from consumers who have already committed to purchasing (or renting) a product (e.g., based on promotion of, or exposure to, the product prior to its launch); the second comes from consumers who are potential buyers of the product; and the third comes from either a networking effect on closely tied (as in a social group) potential buyers from previous buyers (in the case of movie rental and all retail products) or re‐rents (in the case of game rental). In addition, we explicitly formulate into our model dynamic interactions between these sales components, both within and across sales periods. This important feature is motivated by realism, and it significantly contributes to the accuracy of our model. The model is thoroughly tested against sales data for rental and retail products from Blockbuster. Our empirical results show that the model offers excellent fit to actual sales activity. We also demonstrate that the model is capable of delivering reasonable sales forecasts based solely on environmental data (e.g., theatrical sales, studio, genre, MPAA ratings, etc.) and actual first‐period sales. Accurate sales forecasts can lead to significant cost savings. In particular, it can improve the retail operations at Blockbuster by determining appropriate order quantities of products, which is critical in effective inventory management (i.e., it can reduce the extent of over‐stocking and under‐stocking). While our model is developed specifically for product sales at Blockbuster, we believe that with context‐dependent modifications, our modeling approach could also provide a reasonable basis for the study of sales for other short‐Life‐Cycle products.