基于单片机的无线遥控小车研究与实现

本文介绍了一种由STC12C5A60S2单片机控制的无线遥控小车,采用控传和图传独立设计的思想,即数据收发模块进行控制和温度数据的传输,图传模块负责作业环境的图像传输.控传部分以STC12C5A60S2单片机为核心,利用NRF24L01+模块数据收发,L298N电机驱动两路直流电机,使小车完成相应动作;DS18B20负责检测温度,由小车收发模块发射,LCD1602液晶模块显示.系统采用模块化设计,结构紧凑,便于优化,且可靠性能高.     

信任危机、逆向选择与品牌重建——来自网贷之家的经验证据

以中国P2P行业信任危机为背景,借助网贷之家公布的数据,利用面板固定效应模型研究信任缺失情形下的逆向选择问题以及政府和行业协会重建品牌信任的效果,结果表明:P2P行业信任危机下的平台旨在通过建设品牌形象来吸引投资人与借款人的做法是徒劳的,信任缺失导致合规平台的诚信经营并不为公众所认可,长此以往这些平台很可能会退出市场,进而引发逆向选择问题;自上而下的制度建设在重建品牌信任中取得了可喜的成绩,有效缓解并逆转了P2P行业的逆向选择问题,且市场整治初见成效。此研究成果对于目前正在进行的P2P行业整顿具有十分现实的指导意义。     

“海丝”战略背景下闽台海洋经济融合发展研究

党中央在新时期作出的共建21世纪海上丝绸之路的战略决策,对深化区域合作、推动全球经济发展具有重大的影响,更为闽台海洋经济融合发展提供了难得机遇。系统梳理和回顾改革开放以来闽台海洋经济合作的历程及成效,分析21世纪海上丝绸之路战略背景下闽台海洋经济融合发展的新机遇,提出闽台两地应充分发挥优势互补,坚持互利共赢原则,全面加强海洋渔业、航港造船产业、海洋科技产业和海洋观光游憩业的融合发展,共同推动闽台海洋开发合作向纵深发展。     

Analysis of child labour in Peru and Pakistan: A comparative study

This paper analyses child labour participation and its key determinants using data sets from Peru and Pakistan. The results include tests of the ‘Luxury’ and ‘Substitution’ hypotheses that play key roles in recent studies on child labour and child schooling. The results reject both hypotheses in the context of child labour in Pakistan and suggest that income and related variables do not have the expected negative effect on children's work input. Rising wages of adult female labour in Pakistan, and falling adult male wage in Peru lead to increased participation of children in the labour market. The results on the combined country data formally establish the presence of strong individual country effects in the estimated regressions. For example, ceteris paribus, a Peruvian child is more likely to experience schooling than a Pakistani child. However, both countries agree on the positive role that adult female education and infrastructure investment in basic amenities can play in discouraging child labour and encouraging child schooling. Received: 24 August 1998/Accepted: 10 March 1999     

Personal income taxation under mobility, exogenous and endogenous welfare weights, and asymmetric information

This paper analyses how governments should tax labour income accruing to a group of highly skilled and geographically mobile individuals who divide their time or career between several jurisdictions. The analysis differs from previous models on migration and taxation by addressing optimal regulation when agents work for several principals. Optimal taxation is developed for social welfare functions with exogenous and endogenous welfare weights. Marginal income taxes are applied for screening purposes, and the rates are lower with endogenous than with exogenous welfare weights. Received: 22 January 1998/Accepted: 3 July 1999)     

Lower bound of average centered L2-discrepancy for U-type designs

Uniform designs are widely used in various scientific investigations and industrial applications. By considering all possible level permutation of the factors, a connection between average centered L₂-discrepancy and generalized wordlength pattern for asymmetrical fractional factorial designs is derived. Moreover, we present new lower bounds to the average centered L₂-discrepancy for symmetrical and asymmetrical U-type designs. For illustration of the theoretical results, the lower bounds for symmetrical and asymmetrical U-type designs are tabulated, and numerical results indicate that our lower bounds behave well and can be recommended for use in practice.     

On Hotelling’s T2 test in a special paired sample case

In a special paired sample case, Hotelling’s T² test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given.     

Reconsidering the philanthropic foundation minimum payout policy under a “new normal”

With the increasing salience of foundations in many policy fields, and recent changes in market conditions, policies towards foundations designed decades ago seem outdated. In this article we suggest reassessing foundation payout minimums. To examine the impact of payout rates on grantmaking foundations lifespan and performance under “new normal” economics, we simulate multiple foundations lifecycles using Monte Carlo methods in diverse capital market conditions, with varied investment and payout strategies.We find that while under past market regime perpetuity seems to be a given, under more probable future scenarios, foundations might face increasingly early mortality and endowment depletion, limiting their potential impact. Furthermore, lower payout rates allow for higher lifetime grantmaking, higher mean annual grantmaking, and lower giving volatility. Accordingly, we suggest a tiered payout policy, in line with foundations’ missions and proper financial planning.     

基于股价预测的泛证券投资组合策略

本文基于期望效用最大化和L₁-中位数估计研究了在线投资组合选择问题。与EG（Exponential Gradient）策略仅利用单期价格信息估计价格趋势不同,本文将利用多期价格信息估计价格趋势,以提高在线策略的性能。首先,基于多期价格数据,利用L₁-中位数估计得到预期价格趋势。然后,通过期望效用最大化,提出一个新的具有线型时间复杂度的在线策略,EGLM（Exponential Gradient via L₁-Median）。并通过相对熵函数定义资产权重向量的距离,进而证明了EGLM策略具有泛证券投资组合性质。最后,利用国内外6个证券市场的历史数据进行实证分析,结果表明相较于UP（Universal Portfolio）策略和EG策略,EGLM策略有更好的竞争性能。