软件无线电接收通道关键技术分析与应用

本文基于软件无线电的一种典型结构对软件无线电接收系统中的一些关键技术进行了讨论,并结合一个实际系统进行了数学分析。     

To Give or Not to Give: Modeling Individuals' Contribution Decisions

Employing data from a recent national survey on campaign finance, we examine the contribution behavior of individual citizens in the 2000 election. By disaggregating types of contributions, our model enables us to observe potential heterogeneity in the determinants of giving money to parties and candidates. We find that for both types of contributions, the effects of informational resources and solicitation on the decision to contribute outweigh those of financial resources. In addition, we propose both a theoretical and an empirical distinction between the selection effects of solicitation and the stimulus effects of solicitation. By distinguishing between these dual dimensions of solicitation, our analysis provides new insight into the causal linkages between income, solicitation, and contributions. We find that while solicitation increases the likelihood of contributing through selective targeting or rational prospecting, it also does so through a stimulus mechanism.     

Assessing Stability and Change in Criminal Offending: A Comparison of Random Effects, Semiparametric, and Fixed Effects Modeling Strategies

An important theoretical problem for criminologists is an explanation forthe robust positive correlation between prior and future criminaloffending. Nagin and Paternoster (1991) have suggested that the correlationcould be due to time-stable population differences in the underlyingproneness to commit crimes (population heterogeneity) and/or thecriminogenic effect that crime has on social bonds, conventionalattachments, and the like (state dependence). Because of data andmeasurement limitations, the disentangling of population heterogeneityand state dependence requires that researchers control for unmeasuredpersistent heterogeneity. Frequently, random effects probit models havebeen employed, which, while user-friendly, make a strong parametricassumption that the unobserved heterogeneity in the population follows anormal distribution. Although semiparametric alternatives to the randomeffects probit model have recently appeared in the literature to avoid thisproblem, in this paper we return to reconsider the fully parametric model. Viasimulation evidence, we first show that the random effects probit modelproduces biased estimates as the departure of heterogeneity from normalitybecomes more substantial. Using the 1958 Philadelphia cohort data, we thencompare the results from a random effects probit model with a semiparametricprobit model and a fixed effects logit model that makes no assumptions aboutthe distribution of unobserved heterogeneity. We found that with this dataset all three models converged on the same substantive result—evenafter controlling for unobserved persistent heterogeneity, with models thattreat the unobserved heterogeneity very differently, prior conduct had apronounced effect on subsequent offending. These results are inconsistentwith a model that attributes all of the positive correlation between priorand future offending to differences in criminal propensity. Sinceresearchers will often be completely blind with respect to the tenabilityof the normality assumption, we conclude that different estimationstrategies should be brought to bear on the data.     

试论《劳动合同法》的实施效果与运行障碍

<劳动合同法>的颁布和实施引起强烈的社会反响,人们寄望于这部法律扭转当前的劳资格局,建立和谐稳定的劳动关系.但是,这部法律的良好实施取决于用人单位守法的自觉度、劳动者权利意识的觉醒度和劳动保障监察的力度.只有改革现行的社会保险制度,细化<劳动合同法>的抽象条款,加大<劳动合同法>的宣传力度和监察力度,才能取得良好的实施效果.     

《反垄断法》实施的预期效应探究

我国的《反垄断法》是国家基于“公平与效率”的价值追求而创设的市场经济基础·肄法律，旨在维护市场有序竞争，落实国家竞争、产业等经济政策，实现国家经济管理职能。它的实施必将产生一系列预期效应：国家竞争政策统一、反垄断指南具法律效力、“成文法”与“判例法”相融合、为保护国家利益增添新的法律手段以及促进我国行政管理体制的进一步改革等。     

Technical note: Comparison of forensic swabs for intravaginal sampling

This study compared the currently used swab Prionics ForensiX Evidence Collection Kit with the alternatives Prionics ForensiX Evidence Collection Tube SafeDry and Sarstedt Forensic Swab XL. Volunteers provided intravaginal swabs collected with all swab types at specific time points after unprotected sexual intercourse. Quantifiable DNA, detectability of seminal fluid component (prostate specific antigen, PSA) and spermatozoa were evaluated to find the best-performing swab type.While Sarstedt XL showed significantly higher DNA quantities for sperm cell fractions than ForensiX Kit, the more concise PSA test results clearly favour ForensiX SafeDry. Reassuringly, mostly complete autosomal STR profiles of male components were obtained for sperm cell fractions at all time points and tested swabs. Switching to the higher performing ForensiX SafeDry with improved sampling and processing properties will also benefit victims, medical personnel, and investigators.     

Rallying in fear? Estimating the effect of the UK COVID-19 lockdown with a natural experiment

We use a natural experiment to study how the announcement of the UK COVID-19 lockdown affected citizens' attitudes towards the pandemic and the government's response to it. On the day of the lockdown announcement, YouGov ran a survey that captured responses before and after the announcement. Comparison of these responses suggests that the lockdown announcement made people more supportive of the government's response to the crisis but also (perhaps surprisingly) more concerned about the pandemic. Analysis of heterogeneous treatment effects suggests that the announcement narrowed gaps in perceptions of the crisis, increasing support for the government's response especially among those who had been least supportive and increasing concern about the pandemic especially among those who had been least concerned. Overall, the findings highlight a tension inherent in governing during times of crisis: actions that increase people's confidence in government and induce compliance with government directives may also tend to increase anxiety among the population.     

论传统中国的“性情司法”及其实际效应

从文本形式看,传统中国法律的篇章结构、条文体系具有超强的稳定性,有的可以因袭数千年,但法律文本规制与司法实践效应之间存在极大反差,文本的预期价值往往难以实现。其中一个重要原因就是司法主体的性情取向对司法实际效应的影响明显。通过类型化分析,传统中国以皇帝及官员为主的司法主体的性情取向可以归纳为:躬亲狱讼型、宽大仁恕型、秉公行法型、才情饱满型、揆情酌理型、残忍冷酷型、慵懒昏朽型等几大类,它们直接影响到司法的公正性、效率性及社会性效应。研究传统中国法律的价值与功能,既要注意法律文本,更要注意其运作状况及实际效应,考察和分析司法主体的性情司法及其实际效应,不失为一个独特视角。     

全球化、身份政治与法律

美国弗吉尼亚理工大学校园枪击案引发了身份对当代人和当代社会深刻影响实施的思考。身份的连带责任效应表明,拥有某种身份的人所实施的违反道德或法律的行为必然会连累到其他拥有相同身份的人。身份的搭便车效应表明,拥有某种身份的人所做出的高尚或伟大的行为可能会惠及到其他拥有相同身份的人。身份的刻板印象效应表明,社会上形成的对某一身份的刻板印象会影响拥有该身份的个人的命运和社会地位。法律上的很多制度,包括连带责任制度、结社自由制度、反歧视制度等,与身份的这些效应和影响之间存在着密切的关系。     

NEIGHBORHOOD STRUCTURE AND RACE‐SPECIFIC RATES OF INTIMATE ASSAULT*

Addressing the methodological shortcomings of extant research on the racial invariance thesis, race‐specific rates of intimate assault are examined across census tracts in Hamilton County, Ohio. We extend Miles‐Doan's (1998) approach to examining neighborhood structural effects on intimate assault rates in order to test the racial invariance thesis. Findings reveal comparable effects of neighborhood disadvantage and population age structure on assault rates for African‐American males and white males, yet a stronger effect of “disinvestment” (in marriage and in neighborhoods) on rates for African‐Americans. These results conflict with previous city‐level analyses demonstrating stronger structural effects on other violent crime rates for whites.