Efficient improved estimation of the parameters in two seemingly unrelated regression models

For a system of two seemingly unrelated regression equations, this paper proposes a two-stage covariance improved estimator of the regression coefficients. The new estimator is shown to uniformly dominate the present estimators in terms of generalized mean square error criterion. In addition, we also propose the exact generalized mean square error of new estimator.     

The Effect of Forest Management Strategy on Carbon Storage and Revenue in Western Washington: A Probabilistic Simulation of Tradeoffs

The objectives of this study are to understand tradeoffs between forest carbon and timber values, and evaluate the impact of uncertainty in improved forest management (IFM) carbon offset projects to improve forest management decisions. The study uses probabilistic simulation of uncertainty in financial risk for three management scenarios (clearcutting in 45‐ and 65‐year rotations and no harvest) under three carbon price schemes (historic voluntary market prices, cap and trade, and carbon prices set to equal net present value (NPV) from timber‐oriented management). Uncertainty is modeled for value and amount of carbon credits and wood products, the accuracy of forest growth model forecasts, and four other variables relevant to American Carbon Registry methodology. Calculations use forest inventory data from a 1,740 ha forest in western Washington State, using the Forest Vegetation Simulator (FVS) growth model. Sensitivity analysis shows that FVS model uncertainty contributes more than 70% to overall NPV variance, followed in importance by variability in inventory sample (3–14%), and short‐term prices for timber products (8%), while variability in carbon credit price has little influence (1.1%). At regional average land‐holding costs, a no‐harvest management scenario would become revenue‐positive at a carbon credit break‐point price of $14.17/Mg carbon dioxide equivalent (CO₂e). IFM carbon projects are associated with a greater chance of both large payouts and large losses to landowners. These results inform policymakers and forest owners of the carbon credit price necessary for IFM approaches to equal or better the business‐as‐usual strategy, while highlighting the magnitude of financial risk and reward through probabilistic simulation.     

Mining the hidden seam of proximity m-payment adoption: A hybrid PLS-artificial neural network analytical approach

This study investigates the adoption of proximity mobile payment services (PMPS) using, for the first time, an extended version of the decomposed theory of planned behaviour (DTPB) and considering both the linear and non-linear relationships depicted in the proposed model. Based on a two-stage hybrid analytic methodology, the proposed model was validated empirically using a sample of 951 participants. First, partial least squares (PLS) regression was used to identify the significant drivers of PMPS acceptance predictors. Artificial neural networks (ANN) were then used to rank the relative influence of the significant adoption drivers obtained in the previous step. The PLS results indicate that the extended DTPB provides a solid theoretical framework for studying the adoption of PMPS. The results of the PLS-ANN sensitivity analysis confirmed the PLS results regarding the importance of the determinants' of normative and controlling customers’ beliefs, although there were some contradictions concerning the determination of customer attitudes and behavioural intentions towards PMPS usage. The results are discussed and implications are offered.     

改良型生物脱氮除磷水处理综述

现有的城市污水处理厂大多采用A2／O工艺，即英文Anaerobic—Anoxic—Oxic第一个字母的简称（生物脱氮除磷）。此法对污水除磷脱氮较为有效，但由于生物脱氮和生物除磷是相互矛盾的，所以其效果仍不理想。在此介绍一种改良的A2／O工艺，能大大改善污水除磷脱氮效果。     

Improved estimation for the parameters of an inverse gaussian distribution

James-Stein estimators are proposed for the #-parameter of an inverse Gaussian #G# distribution. The estimators of this class have smaller expected quadratic loss than the maximum likelihood estimator usually employed when analysing real sets of data. This problem is also studied for the case of an unknown nuisance parameter. Finally, improved estimators are considered for # in the two sample problem.     

Interval estimation of the common mean

Brown and Cohen (1974) considered the problem of interval estimation of the common mean of two normal populations based on independent random samples. They showed that if we take the usual confidence interval using the first sample only and centre it around an appropriate combined estimate of the common mean the resulting interval would contain the true value with higher probability. They also gave a sufficient condition which such a point estimate should satisfy. Bhattacharya and Shah (1978) showed that the estimates satisfying this condition are nearly identical to the mean of the first sample. In this paper we obtain a stronger sufficient condition which is satisfied by many point estimates when the size of the second sample exceeds ten.     

清水河县工业开发园区改良黄土性能试验研究

针对内蒙古清水河县工业开发园区的湿陷性黄土，开展了石灰粉煤灰改良黄土性能的压缩试验、湿陷性试验，并利用扫描电镜（SEM）进行了微观形貌观察，试验结果表明由于黄土、石灰、粉煤灰之间产生的化学反应，使黄土的压缩性降低、湿陷性消除、颗粒间的孔隙得以填充密实。本文为内蒙古清水河县工业开发园区湿陷性黄土地基处理方面提供一定的试验依据和施工方面的参考。     

基于改进计划行为理论的青少年交通违规行为分析

从儿童的拒绝违规到成人的漠视违规,反映了交通违规行为背后的社会、心理等因素的变化。本文在行为计划理论的基础上,借助外在感知引人社会因素,通过交通违规行为分类,细化不同因素对不同违规行为的影响分析,通过调查问卷的数据收集和理论计算分析,建立面向交通违规行为的改进计划行为理论模型。据此,量化对比分析青少年的交通违规行为的机理和径路,有效解释了青少年违规行为的特征,为青少年违规行为的早期干预,以及成长中的教育、管理等相关政策措施的制定提供理论依据。     

“桃符”是对联的“渊源”吗——对联语言及格律研究之一

"桃符"是对联的"渊源",似乎已成为联苑行家的共识。本文则认为,这其实是一种误解。文章指出:先秦文献中的对偶句式,是对联的原始形态;使对联的原始形态最终发展成为独立的文学形式的,先后是六朝的骈文、唐代的律诗、宋代的词和元代的曲。若论渊源关系,只有它们才称得上是对联的"渊源"。"桃符"不过是使对联"推而用之楹柱"从而获得"楹联"之称的媒介而已。