双瓶颈路段家庭出行者早高峰出行问题研究

针对一次连续出行中两个路段各存在一个瓶颈的双瓶颈路段,研究了家庭出行者早高峰期间先后经过双瓶颈到达学校和工作地的出行行为。首先建立了无收费下的用户均衡模型,接着考虑了拥挤收费模型,并就学校工作地开始时间差值大小的不同展开讨论,分析得出对应系统总出行成本最优时的收费值和收费时窗。研究发现收费管理能够有效降低系统总成本,并且学校和工作地开始时间差较小时的系统总成本更低,最后,通过数值算例验证了高峰时长保持不变,且得出了使得系统出行成本最优时的收费方案。     

The new math as an international phenomenon

The new math was a several-decade-long movement to update school mathematics that began in the mid twentieth century in many countries around the world. It took many forms, but much of it involved the preparation of new instructional materials, including textbooks. Much of the new math activity in Europe and North America was stimulated by conferences and seminars of the Organisation for Economic Cooperation and Development (OECD) in the early 1960s. Although the initial reform efforts addressed secondary school mathematics courses that prepared pupils for tertiary education, those efforts quickly spread to primary school mathematics, to pupils not headed to tertiary education, and to non-OECD countries. Mathematicians and schoolteachers were divided about the direction that the new math reforms took. Although the new math is often deemed a failed endeavor, it changed not only school mathematics but also the way people and countries viewed school mathematics.     

Polynomials: a theme which should not be forgotten

There is a definite movement to remove many of the topics concerning polynomials from the school curriculum. The purpose of this paper is to point out why this movement is misguided and should be reversed.     

Ethnomathematics and political struggles

The paper analyzes and discusses a research study in an ethnomathematics approach, which was developed in a Movimento Sem-Terra (Landless People Movement) settlement in Brazil. The research study is organized as a pedagogical project with peasants, students, teachers and technicians experiencing the construction of an educational process in which local and more global knowledge interacts and where native and technical knowledge are confronted and incorporated. The project allowed the production of a double movement of making community life penetrate the school at the same time as knowledge produced during the pedagogical process pours out from the school space. The approach used in the pedagogical work developed in the Itapui settlement focused on problems of practical and material needs. They were not transmuted into symbolic control problems, indicating other possibilities in the field of ethnomathematics, especially in mathematics education which is carried out with social movements such as the Landless People Movement. Based on her research, the author emphasizes that ethnomathematics finds its most relevant expression when it exposes its social engagement, when it does not treat cultural questions as exotic and unrooted elements, with no commitment to political struggles widespread throughout the world.     

Ethnomathematics and the Brazilian Landless people education

The present study describes and analyses an investigation, shich was developed at a settlement of the Brazilian Landless Movement, a social movement organised to achieve land reform in Brazil. The main purpose of the research consisted in preparing and implementing pedagogical work in the field of mathematics education, from an ethnomathematics perspective, at a public school connected to the Landless Movement, looking at its educational repercussions. They are discussed in this study with regard to the relationship between the pedagogical principles enunciated by the movement for its schools and the perspective of ethnomathematics. The research done showed the potential for this contribution, indicating the possibilities of a specific area of knowledge participating in the construction of an education connected to the interests of the social groups which, throughout history, have been marginalized and excluded.     

A multicriteria approach for optimizing bus schedules and school starting times

In many rural counties pupils on their way to school are a large, if not the largest group of customers for public mass transit. Hence an effective optimization of public mass transit in these regions must include the traffic caused by pupils. Besides a change in the schedules of the buses and the starting times of the trips, the school starting time may become an integral part of the planning process. We discuss the legal framework for this optimization problem in German states and counties and present a multi-objective mixed-integer linear programming formulation for the simultaneous specification of school and trip starting times. For its solution, we develop a two-stage decomposition heuristic and apply it to practical data sets from three different rural German counties.     

A combined statistical approach and ground movement model for improving taxi time estimations at airports

With the expected continued increases in air transportation, the mitigation of the consequent delays and environmental effects is becoming more and more important, requiring increasingly sophisticated approaches for airside airport operations. Improved on-stand time predictions (for improved resource allocation at the stands) and take-off time predictions (for improved airport-airspace coordination) both require more accurate taxi time predictions, as do the increasingly sophisticated ground movement models which are being developed. Calibrating such models requires historic data showing how long aircraft will actually take to move around the airport, but recorded data usually includes significant delays due to contention between aircraft. This research was motivated by the need to both predict taxi times and to quantify and eliminate the effects of airport load from historic taxi time data, since delays and re-routing are usually explicitly considered in ground movement models. A prediction model is presented here that combines both airport layout and historic taxi time information within a multiple linear regression analysis, identifying the most relevant factors affecting the variability of taxi times for both arrivals and departures. The promising results for two different European hub airports are compared against previous results for US airports.     

Historical comments on the use of technology and devices in ICMEs and ICMI

The ICMI Centennial in 2008 gave the occasion to study how the use of technology in teaching mathematics evolved during this period and was transformed by following the general development of technology. Given the key role of Felix Klein in the first international movement for reforming mathematics teaching and in particular for orienting it towards applications, his achievements in the use of geometrical models and artefacts are reported in this historical introduction. The term of ‘model’ proves to be essential in Klein’s efforts to restructure university teaching and to reform secondary school teaching.     

“Natural Philosophy” as a Foundation for Science Education in an Age of High‐Stakes Accountability

Science curriculum and instruction in K‐12 settings in the United States is currently dominated by an emphasis on the science standards movement of the 1990s and the resulting standards‐based high‐stakes assessment and accountability movement of the 2000s. We argue that this focus has moved the field away from important philosophical understandings of science teaching and learning that have their roots in the history of both learning theory and scientific discovery. We offer a philosophical argument, as well as a model for implementation, grounded in the 19th century notion of “natural philosophy,” as well as Dewean progressivism and Piaget's notion of reconstruction through rediscovery, for the important place of the history of science in modern science education. We provide curricular examples of this model, as well as a discussion of how it might be implemented as part of teacher education. We focus our discussion on the elementary and middle school grades, because teachers at these levels tend to have more limited science content knowledge than their secondary school peers, making them more dependent upon curricular materials and thus more heavily influenced by curricular reforms.     

Resource assignment in high school timetabling

This paper explores one aspect of the high school timetabling problem, namely the assignment of resources, such as teachers and rooms, to meetings after times are assigned. Several algorithms, with run times of just a few seconds, are presented and tested on real-world data. The best of these is currently in operation within KTS, a free, public web site for high school timetabling created by the author. A large bipartite matching model, called the global tixel matching, is used to preserve optimality of one key measure of quality as resource assignment proceeds.     

The Tabular Mode: Not Just Another Way to Represent a Function

Understanding mathematical functions as systematic processes involving the covariation of related variables is foundational in learning mathematics. In this article, findings are reported from two investigations examining students' thinking processes with functions. The first study focused on seven middle school students' explorations with a dynamic physical model. Students were videotaped during the 20‐ to 45‐minute sessions occurring two or three times per week over a period of 2 months, and students' written work was collected. The second investigation included 19 preservice elementary and middle school teachers enrolled in a course focusing on a combination of mathematical content and pedagogy. Participants' written problem‐solving work and reflective writing were collected, and participants were individually interviewed in 50‐minute videotaped sessions. Results from both investigations indicated that students often relied on a table, or some variation of a table, as a cognitive link advancing the development of their reasoning about underlying function relationships.     

Lot Streaming in a Two-stage Flow Shop with Set-up,Processing and Removal Times Separated

This paper considers the job (lot) scheduling problem for two-stage flow shops in which the movement of transfer batches (sublots) from the first stage to the next are allowed. Set-up, processing and removal times are considered as separable and independent of the order in which jobs are processed at any of two stages. An optimal transfer batch sizing and scheduling algorithm which has an objective of minimizing the maximum flow time (makespan) is developed and demonstrated by a numerical example.     

Solving a school bus scheduling problem with integer programming

In many rural areas in Germany pupils on the way to school are a large if not the largest group of customers in public transport. If all schools start more or less at the same time then the bus companies need a high number of vehicles to serve the customer peak in the morning rush hours. In this article, we present an integer programming model for the integrated coordination of the school starting times and the public bus services. We discuss preprocessing techniques, model reformulations, and cutting planes that can be incorporated into a branch-and-cut algorithm. Computational results show that in our test counties a much lower number of buses would be sufficient if the schools start at different times.     

三维弹性问题无网格分析的奇异杂交边界点方法

提出了一种求解三维线弹性问题的奇异杂交边界点方法．将修正变分原理与移动最小二乘法结合起来,利用了前者的降维优势和后者的无网格特性．使用刚体位移法处理方法中的强奇异积分,提出了一种自适应的积分方案,解决了原有的杂交边界点方法中存在的“边界层效应”．在该方法中,将基本解的源点直接布在边界上,避免了在正则化杂交边界点法中不确定参数的选取．三维弹性力学问题算例体现了这些特点．结果表明该方法与已知的精确解符合较好,同时研究了影响该方法精度的一些参数．     

Values in Japanese mathematics education: their historical development

Individual mathematics teachers may value different aspects of teaching and learning mathematics, but at the same time their value systems are under the influence of socially shared values. This paper describes such values in Japanese mathematics education from a historical and normative perspective. After the introduction of Western mathematics into the modern school system in the Meiji period (1868?C1912), the people of Japan struggled to adapt and absorb it onto the foundation of Japanese tradition. In the subsequent development of Japanese mathematics education, the integration of both practical and theoretical aspects have been issues, alongside changes in educational focus and in society at large, which are symbolically represented by the enrolment rates at all of elementary, secondary, and tertiary education levels. Mathematics education in Japan has also been subject to international influences, such as the reform movement and the modernization movement, at critical junctures in its development. Key concepts such as mathematical ideas, mathematical thinking, and mathematical activities are traces of such historical efforts by the Japanese mathematics education community, and represent their socially shared values.     

System Regularity and Overtaking Rules in Bus Services

A detailed analysis on the effects of different overtaking rules upon scheduled and unscheduled urban bus services was carried out. The analysis used computer models, which were developed to simulate bus operation strategies with or without overtaking and possibly parallel loading.Permitting overtaking in unscheduled services was found to reduce the journey time of the buses but resulted in a higher degree of irregularity in the service. Scheduled services, in contrast, appeared to be more reliable when overtaking was permitted. In such services, permission for overtaking reduced the waiting times of passengers as a result of faster journeys and a more regular service.     

Science Self‐Efficacy and School Transitions: Elementary School to Middle School,Middle School to High School

This study examined the science self‐efficacy beliefs of students at the transition from elementary school (Grade 6) to middle school (Grade 7) and the transition from middle school (Grade 8) to high school (Grade 9). The purpose was to determine whether students' perceived competence is impacted at these important school transitions and if the effect is mediated by gender and ethnicity. Science self‐efficacy was measured through a modified Self‐Efficacy Questionnaire for Children, which was adapted to focus specifically on science self‐efficacy. Multiple ordinary least squares regression was used to analyze the data. Two models were developed, one using ninth grade as the comparison group and the other using sixth grade as the comparison group. In each model, the independent variables (grade level, gender, and ethnicity) were regressed on the dependent variable, science self‐efficacy. The most striking finding was the large and significant decline in science self‐efficacy scores for ninth graders at the transition to high school. We also found that females and Hispanic students had lower scores across grades as compared to males and Caucasians. How these results relate to existing studies, and implications for practice and future research are discussed.     

Navigating Schooled Numeracies: Explanations for Low Achievement,in Mathematics of UK Children From Low SES Background

The intention of the research reported here was to seek explanations for low achievement in school mathematics, as conventionally assessed, that derive from broad understandings of mathematics as social. Such a broad social perspective can provide explanations for low achievement, which could lead to different understandings and hence to different teaching approaches. This study centered on 5- to 8-year-old children from a White working-class area in England. Data were collected during visits to the children in school, in their homes, and in the broader community over a 3-year period. Parents, teachers, and other professionals in the broad school context were interviewed, and data were also collected from school documents and policy statements. Interpretations of these data in terms of ways of understanding children's achievements in school mathematics are put forward. The potential effects of these factors on low schooled numeracy attainment are discussed, together with some possible strategic implications for practice and policy.     

Phase-type distributions for failure times

Phase-type distributions describe the random time taken for a Markov process to reach an absorbing state. In the context of component failure, sequential movement through the transient states (phases) of such a system could describe the ageing process with movement out of these states (absorption) corresponding to failure. Thus, the lifetime of a component is the absorption time and the probability distribution of these times can be written in terms of the solution of a system of differential equations for which there are many convenient computational algorithms. A variety of different distributions is possible by varying the parameters of the process and hazard rates of various shapes can be constructed, allowing different patterns of variation in observed data to be modelled. These distributions are applied to some industrial data-sets and further features of the processes discussed.