Interpreting DNA Evidence: A Review

The paper provides a review of current issues relating to the use of DNA profiling in forensic science. A short historical section gives the main statistical milestones that occurred during a rapid development of DNA technology and operational uses. Greater detail is then provided for interpretation issues involving STR DNA profiles, including:

• – methods that take account of population substructure in DNA calculations;

• – parallel work carried out by the US National Research Council;

• – the move away from multiple independence testing in favour of experiments that demonstrate the robustness of casework procedures;

• – the questionable practice of source attribution 'with reasonable scientific certainty';

• – the effect on the interpretation of profiles obtained under increasingly sensitive techniques, the LCN technique in particular;

• – the use of DNA profiles as an intelligence tool;

• – the interpretation of DNA mixtures.

Experience of presenting DNA evidence within UK courts is also discussed. The paper then summarises a generic interpretation framework based on the concept of likelihood ratio within a hierarchy of propositions. Finally the use of Bayesian networks to interpret DNA evidence is reviewed.     

An integrated arterial coordinated control model considering green wave on branch roads and pedestrian crossing time at intersections

Urban fine management needs scientific traffic management methods and efficient signal control programs. Green wave control is usually used to facilitate the unban traffic. However, maximum bandwidth optimization on arterial traffic signal timing is usually yielded from the sacrifice of the branch road. The green wave on branch roads and pedestrian crossing time at intersections are often neglected. In this paper, an extended integrated green wave control method is presented to solve the coordinated control issue, which considers green time constraints to ensure necessary time for vehicles on branch roads and pedestrian crossing time at intersections. Non-coordinated phase saturation is first introduced to describe the green time on branch roads. Next, the arterial roads are partitioned to enlarge the green wave bandwidth and an extended green wave optimization model with green time constraints is proposed. Combined with the green wave searching method, an improved genetic algorithm is applied. Finally, a real-world case study in Shenzhen, China, is employed to assess the model. Results show the proposed model can (1) reach the same public green time as in the traditional method and (2) increase the average sub-green wave bandwidth to improve the signal control.     

盈余管理:动因及后果——兼与利润操纵的比较

盈余管理的动因有终极动因和中介动因,其根本目的是实现自身效用或公司市场价值最大化,其经济后果有弊也有利.而利润操纵完全是为了谋取私利,且不惜牺牲其他相关人的利益,故它是百害而无一利的.为促进资本市场的理性发展,应当完善相关的法律法规以对二者进行规避.     

HETEROGENEITY IN ORDERED CHOICE MODELS: A REVIEW WITH APPLICATIONS TO SELF‐ASSESSED HEALTH

Discrete variables that have an inherent sense of ordering across outcomes are commonly found in large data sets available to many economists, and are often the focus of research. However, assumptions underlying the standard ordered probit (which is usually used to analyse such variables) are not always justified by the data. This study provides a review of the ways in which the ordered probit might be extended to account for additional heterogeneity. Differing from other reviews in scope, application and relevance in economic settings, a series of issues pertaining to choices of variables, and the economic assumptions underlying each model are discussed in the context of measuring the underlying health of respondents. The models are applied to a wave of the household, income and labour dynamics in Australia survey, in order to check the appropriateness of such assumptions in an applied context.     

Time-dependent lottery preference and the cross-section of stock returns

Highlighting the importance of benchmark to identify lottery-like payoffs of stocks, this study proposes that investors’ lottery preference is formed toward tracking stocks’ performance over time. Accordingly, we develop a strategy based on time-dependent maximum daily return (denoted as TMAX) by buying (short selling) stocks with the most recent maximum daily returns (MAX) ranked in the bottom (top) decile of the historical distribution. The TMAX strategy generates significant premium that subsumes the profitability of Bali, Cakici, and Whitelaw’s (2011) MAX strategy, but not vice versa. A major advantage of the TMAX strategy is its time-invariant profitability across different periods and sentiment states. Further analyses show that the TMAX premium can be explained by shorting flow and behavioral theories, supporting the time-dependent feature of lottery preference.     

中国省际环境基本公共服务绩效差异分析

利用"纵横向"拉开档次评价法实证分析中国30个省级政府2002~2011年的环境基本公共服务绩效,结果表明省际差异显著。中西部大部分地区绩效整体逐年上升但总得分偏低,东部综合绩效水平明显高于中西部;环境安全性服务和环境信息性服务占综合绩效得分比重明显偏小。为此,应加大对中西部省份环境基本公共服务的财政投入,实施差异化区域性环境基本公共服务战略;同时增加对环境安全性服务和环境信息性服务的投入,提升环境基本公共服务整体水平。     

时变Copula模型的非参数推断

运用Copula模型研究金融变量之间的相关结构,是近年来金融分析中的一个热点,如何估计Copula模型中的时变参数则是一个重点和难点问题。本文从非参数建模思想为切入点,提出经验分布函数—局部极大似然法(ECDF-LML)估计Copula函数中的时变参数,研究了Copula模型参数是否时变的统计假设检验问题。最后通过大量随机模拟研究验证了本文所提出的方法较DCC-MGARCH方法在刻画随机变量动态相关性方面更具优越性且很稳健。     

The optimal bid/ask spread in a Specialist System

In this work we propose a simple market model where some features of the Specialist System are analyzed. In particular, the specialist's obligation to display bid/ask quotes on the book within the bounds imposed by the Exchange is considered. The proposed model allows to analyze the effects of the specialist's interventions on the short term dynamics of bid/ask prices and address a relevant market design issue, that is determination and analysis of the optimal endogenous upper bound that - according to economic conditions - should be imposed by Stock Exchange on the quoted bid/ask spread. The institutional details are summarized in a few structural parameters and the focus is on the aggregate effects of excess demand/supply.     

The maximum capture per unit cost location problem

This paper considers the problem of siting p new facilities of an entering firm to a competitive market so as to maximize the market share captured from competitors per unit cost. We first formulate the problem as a mixed 0-1 fractional programming model, in which we incorporate the fixed cost and transportation cost. The model can deal with the case where some demand nodes have two or more possible closest servers. We then re-formulate the problem as a 0-1 mixed integer linear program. We use a one-opt heuristic algorithm based on the Teitz-Bart method to obtain feasible solutions and compare them with the optimal solutions obtained by a branch-and-bound algorithm. We conduct computational experiments to evaluate the two algorithms. The results show that both algorithms can solve the model efficiently and the model is integer-friendly. We discuss other computational results and provide managerial insights.     

On the Application of Conditional Independence to Ordinal Data

A special log linear parameterization is described for contingency tables which exploits prior knowledge that an ordinal scale of the variables is involved. It is helpful, in particular, in guiding the possible merging of adjacent levels of variables and may simplify interpretation if higher-order interactions are present. Several sets of data are discussed to illustrate the types of interpretation that can be achieved. The simple structure of the maximum likelihood estimates is derived by use of Lagrange multipliers.