合舍系统及其定理的能行证明

以合舍作为唯一初始联结词,在括号表示法中,只需要使用一对左右括号"「」"就可以无歧义地表达所有的逻辑函数,并进而建立包括括号"「」"的引入规则和消去规则在内的自然推演系统NPD1,可以证明该系统与通常的命题逻辑推理系统相等价.通过定义可以给出常见的其他联结词并证明相关定理.受亚里士多德化归思想的启发,构建了系统NPD1的7组化归规则,并给出化归程序;依据此程序,可以将系统内的任一定理能行地化归为一个形如的公式.     

弘扬自然辩证法传统 建设科学技术学学科群

本文回顾了我国自然辩证法学科和学科群的发展过程,分析了其间的广义理论和狭义理解、分歧和共性,探讨了终将从广义上延拓成科学技术学一级学科,从狭义上形成二级学科群的合理性和现实可能性.基于坚定自然辩证法原理作为科学技术学基础理论及学科建设指南的必然性,建议扩大<自然辩证法研究>副标题的内涵,将目前冗长的副标题改变成简洁的"关于科学技术学的理论性杂志".     

高校贫困大学生就业问题分析与对策研究

随着社会的发展，时代的进步，人们的人才观和择业观也随之在变化，于是大学生就业难已成为社会关注的热点和难点问题，其中来自于贫困生的就业压力尤为突出。面对人才市场竞争的加剧，高校贫困毕业生就业工作的特殊性也就日益突出。本文从高校贫困生的现状和成因出发，针对高校贫困生就业出现的问题进行分析，从而为高校贫困生的就业提供必要的对策方面的帮助。     

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"。     

On the existence of maximum likelihood estimates for weighted logistic regression

The problems of existence and uniqueness of maximum likelihood estimates for logistic regression were completely solved by Silvapulle in 1981 and Albert and Anderson in 1984. In this paper, we extend the well-known results by Silvapulle and by Albert and Anderson to weighted logistic regression. We analytically prove the equivalence between the overlap condition used by Albert and Anderson and that used by Silvapulle. We show that the maximum likelihood estimate of weighted logistic regression does not exist if there is a complete separation or a quasicomplete separation of the data points, and exists and is unique if there is an overlap of data points. Our proofs and results for weighted logistic apply to unweighted logistic regression.     

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.     

中国省际公共资本存量估算:概念、框架与指标构建

文章通过合理界定公共资本内涵及统计范围,运用资产价值公式推导资产折旧率的时间序列数据,基于永续盘存法、“年龄—效率”函数谨慎测算1985-2014年中国省际公共资本存量和生产性公共资本存量。结果表明,与公共资本存量相比,生产性公共资本存量通过综合考虑资产退役及效率损失,更能反映实际服务于生产过程的公共资本规模。总体上,中国生产性公共资本存量自1993年以来增速明显加快,金融危机时期积极财政政策的实施进一步推动公共资本存量的迅速积累;区域上,生产性公共资本存量由东向西呈阶梯式分布,沿海地区公共资本存量处于领先水平,而大西北地区的公共投资呈严重不足状态。