应用条码技术进行食品溯源的可行性分析

分析了食品质量安全问题的形成机制，提出了食品溯源过程的实施原则，最后指出了运用条码进行食品安全溯源的优势。     

石油工业也应建立专用计量器具检定系统

针对石油天然气行业专用计量器具的检定系统表这一现状进行了分析，提出检定系统表是量值溯源的唯一依据，没有它工作计量器具的允许误差就缺少科学依据．并对如何建立这一系统提出了建设性意见。     

基于单片机的红外音频信号发射遥控系统的设计与研究

红外线音频信号发射系统,是以红外线作为载波光源,把声音调变在载波中,通过空气从发射端传送至接收端的过程。本系统采用调频的方式来做调变,它比振幅调变及相位调变的讯噪比高、失真度低、受环境干扰程度低,又比脉波码调变来的经济。发射光源选取红外光优点则在于不容易被其他电器干扰,保密性能好,无接线、不怕阻隔。     

锦纶聚合中电伴热应用探讨

电伴热技术,尤其是管道电伴热技术国外已发展相当成熟,而国内研究及应用相对滞后,在当今提倡环保、节能、经济效益条件下,电伴热技术显得更加重要,文章分析了电伴热产品特点,探讨了电伴热技术在锦纶聚合中应用的可行性。     

管道对接焊接接头射线检测标准比较分析

JB/T 4730-2005《承压设备无损检测》和SY/T 4109-2005《石油天然气钢质管道无损检测》在无损检测行业中都有着广泛的应用,但两个标准有一定的差别,在具体应用中,应根据两个标准的各自特点进行综合考虑。文章对两个标准射线部分的不同之处进行比较,目的是便于无损检测人员能更好地理解标准,更加准确地使用标准,从而保证无损检测工作质量和工程焊接质量。     

基于二维码的果蔬农产品追溯系统初步设计

在分析建立一个完善的果蔬农产品追溯系统必要性及迫切性的基础上,描述目前国内农产品的主要追溯模式,对相关追溯技术性能进行对比分析。经过系统需求分析展开系统结构和数据流程分析,初步设计基于二维码技术的果蔬农产品追溯系统整体框架,并进行相应的功能设计,为实现果蔬农产品从“农田到餐桌”的追溯起到良好的借鉴作用。     

Assessing causal inference problems with Bayesian process tracing: the economic effects of proportional representation and the problem of endogeneity

ABSTRACT

In recent years, causal process tracing is becoming increasingly formalised as scholars have begun to follow Bayesian logic and thereby manage to combine the interpretative and contextual nuance of older forms of process tracing with the inferential rigours of Bayesian analysis. This paper illustrates the basic logic of Bayesian process tracing by drawing on the political economy literature that studies the social policy and economic effects of electoral systems. It compares and contrasts how each approach deals with the problem of endogeneity.     

Process tracing of extensive and intensive processes

ABSTRACT

This essay briefly analyzes the introduction of process tracing to the political science and political economy methodological toolkit. It then proposes a theory-guided variant of process tracing and distinguishes between its application in extensive and intensive type of processes. It argues that the comparative advantage of process tracing vis-à-vis other social sciences research methods lies in its potential to uncover the causal mechanisms that link the constitutive events of intensive type of processes. It shows that theory-guided process tracing of intensive processes can be successfully applied to illustrate, test and produce theory.     

Mechanisms,Bayesianism, and process tracing

ABSTRACT

This essay examines the role of mechanisms and Bayesian inference in process tracing. With respect to mechanisms, I argue that the core of process tracing with causal inference is the identification of mechanisms understood as intervening events. Events are different from standard intervening variables when used with process tracing, because events are treated as sets in which cases can have membership. With respect to Bayesian analysis, I concur with recent writings that suggest Bayesian inference is at the heart of process tracing. The Bayesian nature of process tracing explains why it is inappropriate to view qualitative research as suffering from a small-N problem and certain standard causal identification problems. More generally, the paper shows how the power of process tracing as a qualitative methodology depends on and grows from its set-theoretic underpinnings.     

一种汽车零部件批次管理装配信息精确追溯过程研究

汽车零部件产品追溯过程是实现缺陷汽车召回的关键,如何实现汽车产品批次精确追溯是汽车制造企业的一个难题,追溯方法的选择直接导致缺陷汽车召回批次和数量是否正确。以物流过程中的零件批次信息为源头来控制汽车装配时追溯信息、实现精确追溯是一种可行的方案,为汽车制造厂进行汽车零部件产品精确追溯提供一种思路。