浅谈燃气企业的局域网管理

从燃气企业的角度,介绍了企业局域网规划的重要性和网络安全,详述了使用AD活动目录进行集中管理、内网中安装WSUS服务器等两种网络系统的管理和维护方法。     

棘腹蛙繁殖生态的初步研究

本文报道了湘西棘腹蛙繁殖生态的初步研究结果。棘腹蛙多数在3月中、下旬出蛰，5月至8月为每繁殖期，6月至7月为繁殖盛期。同时，对棘腹蛙天然产卵场及其环境条件、第二性征与性成熟年龄，怀卵量与成熟系数、生殖行为和卵群形态等方面进行了研究。所获得的资料，为人工养殖棘腹腹蛙提供了理论依据。     

“透明的荒诞”与“纯洁的逻辑”——论《卡利古拉》中的暴虐启蒙

加缪戏剧主人公古罗马暴君卡利古拉对于"不可能之域"的追求,是以对价值领域里的"不可能性"的突破来代替对事实领域的"不可能性"的征服,两者的错位进一步凸显了存在的荒诞性。卡利古拉的所有暴行皆意在某种表达,这种表达采取了一贯的纯粹而执著的逻辑形式,以"求真去蔽"为目的,这一切构成某种关于存在之荒诞真相的"暴虐启蒙"。     

Statistical considerations in clinical trial design with event-free survival as the primary efficacy endpoint

In late-phase confirmatory clinical trials in the oncology field, time-to-event (TTE) endpoints are commonly used as primary endpoints for establishing the efficacy of investigational therapies. Among these TTE endpoints, overall survival (OS) is always considered as the gold standard. However, OS data can take years to mature, and its use for measurement of efficacy can be confounded by the use of post-treatment rescue therapies or supportive care. Therefore, to accelerate the development process and better characterize the treatment effect of new investigational therapies, other TTE endpoints such as progression-free survival and event-free survival (EFS) are applied as primary efficacy endpoints in some confirmatory trials, either as a surrogate for OS or as a direct measure of clinical benefits. For evaluating novel treatments for acute myeloid leukemia, EFS has been gradually recognized as a direct measure of clinical benefits. However, the application of an EFS endpoint is still controversial mainly due to the debate surrounding definition of treatment failure (TF) events. In this article, we investigate the EFS endpoint with the most conservative definition for the timing of TF, which is Day 1 since randomization. Specifically, the corresponding non-proportional hazard pattern of the EFS endpoint is investigated with both analytical and numerical approaches.     

Changes in risky gambling prevalence among a New Zealand population cohort

Evidence suggests that problem gambling is an unstable state where gamblers move into and out of risk over time. This article looks at longitudinal changes in risky gambling and the factors associated with an increased risk (measured by the Problem Gambling Severity Index [PGSI]) in the current New Zealand context, which has experienced a doubling of the electronic gaming machine (EGM) market over the last two decades. Respondents from a nationally representative baseline sample (n = 2672) were recontacted two years later to assess changes in gambling behaviours. Among the 901 respondents reached at follow-up, average gambling risk increased over time, and the prevalence of those who had at least some level of gambling risk (i.e. low-risk or greater) more than doubled (from 4.7% to 12.4%). The majority (80.2%) of those who were at risk at follow-up had not been at risk at baseline. Multivariate linear regression analyses show that the predictors of low to moderate increased risk include Pacific ethnicity; high neighbourhood deprivation status; baseline frequent, continuous gambler type; baseline PGSI status; and playing EGMs. These findings highlight the need to develop theories of gambling addiction trajectories and to identify the earliest point along the trajectory where public health interventions should occur.     

Power analysis for clustered non-continuous responses in multicenter trials

Power analysis for multi-center randomized control trials is quite difficult to perform for non-continuous responses when site differences are modeled by random effects using the generalized linear mixed-effects model (GLMM). First, it is not possible to construct power functions analytically, because of the extreme complexity of the sampling distribution of parameter estimates. Second, Monte Carlo (MC) simulation, a popular option for estimating power for complex models, does not work within the current context because of a lack of methods and software packages that would provide reliable estimates for fitting such GLMMs. For example, even statistical packages from software giants like SAS do not provide reliable estimates at the time of writing. Another major limitation of MC simulation is the lengthy running time, especially for complex models such as GLMM, especially when estimating power for multiple scenarios of interest. We present a new approach to address such limitations. The proposed approach defines a marginal model to approximate the GLMM and estimates power without relying on MC simulation. The approach is illustrated with both real and simulated data, with the simulation study demonstrating good performance of the method.     

基于高维波动率网络模型的股票市场风险特征研究

波动率是金融风险管理研究的重要内容之一。本文基于复杂网络理论和数据挖掘技术提出股票市场的高维波动率网络模型。首先运用互信息度量不同股票价格波动之间的相关关系,其次对股票市场不同周期下的波动情况建立度的中心势、平均距离、幂律分布等网络拓扑指标,再次根据这些指标利用Prim算法构建出高维波动率网络模型,最后运用Newman-Girvan算法对股票价格波动率的相关性进行分层研究。高维波动率网络模型突破了传统波动率模型关于变量维数的限制,能够在依赖少量假设的基础上,挖掘出多个金融市场主体间的相互关系,反映金融市场的风险特征及网络拓扑性质。实证结果发现：与常用的Pearson相关系数法相比,在互信息框架下,股价波动的非线性相关关系得到了更好的度量;股票市场的整体波动性与个股波动率相关性变化趋势相反,市场处在高波动时期资产组合分散化效果较好;网络中存在少量度数大的关键节点和中心节点,风险通过这些节点可以迅速传递到整个市场;股票市场的运行具有明显的行业聚集现象;网络分层研究进一步直观的展现了风险在层与层之间的传递规律和与之对应的行业特征。高维波动率网络模型为挖掘股票市场的风险特征与管理金融风险提供了一个新的工具。     

制度分析:对新制度主义的一种解读

从近代制度经济学到新制度经济学,从经济学领域到社会学领域,组织研究中的制度分析一直体现出很强的学术解释能力,同时不断地扩大着自己的适用范围。本文以新制度主义的经济学背景为起点,探讨了制度分析在不同学科领域中体现出来的视角差异,并重点阐述了组织社会学中的新制度主义理论学派及其相关实证研究的发展,旨在从根本上理解制度分析如何成为一种广为接受的跨学科研究范式。     

Challenges in Meeting the Mental Health Needs of Urban Asian American Adolescents: Service Providers’ Perspectives

Although Asian American youth are often viewed as the model minority group who are doing well, research with youths, parents, and school personnel have documented significant unmet mental health needs among this population. However, little is known about the perspectives of service providers who work with Asian American youth in afterschool and mental health care settings with respect to what they perceive as challenges meeting the psychosocial needs of the population. The current exploratory study used Consensual Qualitative Research to analyze in-depth interviews with mental health providers, educators, and advocates working with Asian American youths in a multiethnic large urban environment. Results found that service providers were attuned to the multiple needs of the community but also spoke of challenges in meeting basic and psychological needs due to difficult family dynamics, structural stressors (e.g., economic and legal), and societal stigma and discrimination. We draw implications for providing more integrated services across different levels of urban Asian American adolescents’ ecological system to better meet the psychosocial challenges facing this population.     

“三元”知识的运作管理模式:理论与应用

"三元"知识理论的提出是管理史上一次突破性的进展,但这一理论及其应用是尚未受到充分研究的管理领域。依据感性知识、理性知识和活性知识的基本分野与关联,构建起一个"三元"知识的运作管理模式:以操作与实践为支柱、以战略与制度为后盾、以价值观与理想为动力。这一管理模式在人力资源管理、知识管理和战略管理领域有着巨大的应用价值,而且,"三元"知识运作管理模式蕴涵的批判性学习较之于其他学习方式更胜一筹。