Introducing a general class of species diversification models for phylogenetic trees

Phylogenetic trees are types of networks that describe the temporal relationship between individuals, species, or other units that are subject to evolutionary diversification. Many phylogenetic trees are constructed from molecular data that is often only available for extant species, and hence they lack all or some of the branches that did not make it into the present. This feature makes inference on the diversification process challenging. For relatively simple diversification models, analytical or numerical methods to compute the likelihood exist, but these do not work for more realistic models in which the likelihood depends on properties of the missing lineages. In this article, we study a general class of species diversification models, and we provide an expectation-maximization framework in combination with a uniform sampling scheme to perform maximum likelihood estimation of the parameters of the diversification process.     

A practical approach to determining critical macroeconomic factors in air-traffic volume based on K-means clustering and decision-tree classification

A given region's volume of air passengers and cargo is frequently taken to represent its economic development. This research proposes a practical methodology for investigating the inherent patterns of the relationships between air-traffic volume and macroeconomic development, utilizing data-mining techniques, including K-means clustering and Decision Tree C5.0 classification. Using the case of Taiwan from 2001 to 2014, 32 potential macroeconomic factors ascertained from a literature review were combined with air-traffic volume data to establish a 168-month dataset. After this dataset was grouped into five clusters, decision trees were implemented to determine its critical macroeconomic characteristics. The resulting four critical factors and their thresholds were the Information and Electronics Industrial Production Index (IE Index), at 83.22; National Income Per Capita, at US$3,222; Employed Population, at 10.134 million; and the Japanese Nikkei 225 Stock Average, at 10564.44. Among these, the IE Index was found to be the first critical factor relating to air-traffic volume as well as the only characteristic to distinguish Cluster V – 58 consecutive months from March 2010 to December 2014 inclusive – among others, and the reasonableness of this finding was confirmed via examination of detailed air-traffic statistics. Besides, the effectiveness of the four identified critical factors as predictive variables were validated by comparing forecasted results with actual air traffic volume from 2015 to 2016. Understanding these four critical factors and their relative importance is of great value to policymakers seeking to allocate limited resources optimally and objectively. Therefore, as an effective and efficient means of capturing significant and explainable macroeconomic factors influencing air-traffic volume, the proposed methodology can be applied to strategy formulation, operations management, and investment planning by governments, airports, airlines, and related entities.     

A hybrid clustering and classification approach for predicting crash injury severity on rural roads

As a threat for transportation system, traffic crashes have a wide range of social consequences for governments. Traffic crashes are increasing in developing countries and Iran as a developing country is not immune from this risk. There are several researches in the literature to predict traffic crash severity based on artificial neural networks (ANNs), support vector machines and decision trees. This paper attempts to investigate the crash injury severity of rural roads by using a hybrid clustering and classification approach to compare the performance of classification algorithms before and after applying the clustering. In this paper, a novel rule-based genetic algorithm (GA) is proposed to predict crash injury severity, which is evaluated by performance criteria in comparison with classification algorithms like ANN. The results obtained from analysis of 13,673 crashes (5600 property damage, 778 fatal crashes, 4690 slight injuries and 2605 severe injuries) on rural roads in Tehran Province of Iran during 2011–2013 revealed that the proposed GA method outperforms other classification algorithms based on classification metrics like precision (86%), recall (88%) and accuracy (87%). Moreover, the proposed GA method has the highest level of interpretation, is easy to understand and provides feedback to analysts.     

The Financial Implications of Using Decision Tree Analysis for Publicly Funded Health Care Screening in Canada

This article demonstrates that decision trees have several applications in screening for incidences of various cancers in the publicly funded health care system of Canada. This article reviews previous research on the design of various types of decision trees to identify the relevant decision-making parameters that should be incorporated into enhanced usage of decision trees. This article proposes a methodology for screening breast and prostate cancers. While an accounting is made for various financial costs and benefits, comments are made on the limitations of the modeling exercise through identification of problems in assigning probabilities, the use of samples in ascertaining population parameters, ethical concerns, and measuring a cost per life year. This article concludes with prospects for future research including private sector versus public sector financing and the incorporation of opportunity costs into the decision-making process.     

浅谈观赏草在高尔夫球场的应用

观赏草品种多样,色彩丰富,适应性强。随着高尔夫运动在我国的迅速发展,人们对高尔夫球场的景观和竞技性的要求也不断提高。观赏草在高尔夫球场发球台周边、高草区、障碍区等合理运用能够增添球场色彩和丰富球场战略性。     

东北园林树木信息系统的研究开发

将东北地区内具有观赏价值的木本植物资源收集成一个多媒体数据库,利用现代信息技术开发成管理信息系统软件。系统具有数据录入、查询、统计与分析、图片浏览和系统维护等主要功能,具有功能全面,操作方便,数据查询灵活多样、数据信息量大,数据处理速度快捷的特点,该系统为从事园林树木科研、决策、教学、生产和管理等部门的用户提供了一个对东北现存的木木观赏植物资源的概况比较系统和全面了解的应用软件,用户可应用系统的数据为自己的研究、生产和学习服务。     

曲阜观赏植物资源及其开发利用与保护对策

在对曲阜植物资源调查的基础上,分析研究了曲阜观赏植物资源现状;该区观赏植物资源可分为古树名木、栽培观赏植物和野生观赏植物3种类型,其中野生观赏资源有63科150属236种;对曲阜观赏植物资源的开发利用和保护提出了建议。     

An extensive form interpretation of the private core

Summary. The private core of an economy with differential information, (Yannelis (1991)), is the set of all state-wise feasible and private information measurable allocations which cannot be dominated, in terms of ex ante expected utility functions, by state-wise feasible and private information measurable net trades of any coalition. It is coalitionally Bayesian incentive compatible and also takes into account the information superiority of an individual. We provide a noncooperative extensive form interpretation of the private core for three person games. We construct game trees which indicate the sequence of decisions and the information sets, and explain the rules for calculating ex ante expected payoffs. In the spirit of the Nash programme, the private core is thus shown to be supported by the perfect Bayesian equilibrium of a noncooperative game. The discussion contributes not only to the development of ideas but also to the understanding of the dynamics of how coalitionally incentive compatible contracts can be realized. Received: July 21, 2000; revised version: January 16, 2001     

Using photography to elicit grazier values and management practices relating to tree survival and recruitment

Integrating conservation and agricultural production is a major challenge globally. The upper Lachlan catchment of Australia is dominated by livestock grazing, and is threatened because most native woodland vegetation has been cleared. A third of all remaining tree cover occurs as scattered trees in grazing pastures. These scattered trees are dying from old age and are not regenerating due to grazing pressure. Previous work has revealed management strategies that are more likely to maintain tree cover, such as low-input rotational grazing. We asked graziers to photograph significant features on their properties, and used the images as prompts in later interviews. This elicited graziers’ landscape values and other drivers of their management practices related to tree cover. The targets that our 25 case landholders chose to photograph, and the ways they discussed them in later interviews, reflected the focus of past education and incentive programs, suggesting that well-designed policies, educational messages and incentives do seem to reach landholders and result in improved practices. For example, many landholders reported management activities related to the protection of large woodland patches or the maintenance of coarse woody debris. The maintenance of scattered tree cover has not been a focus of policy initiatives in the past. Despite this, the narratives elicited by photos of isolated and scattered trees showed graziers valued them and were aware of and concerned about their decline, yet lacked knowledge about how to protect and regenerate them. Graziers urgently need unambiguous advice and practical assistance to help them adapt their practices to maintain scattered trees in the long term.