论B2B反向拍卖采购模式的选择

B2B在线反向拍卖作为一个有发展前途的重要的电子采购工具已经出现,目前的研究主要停留在案例分析上,迄今为止还没有人运用模型来系统的评估反向拍卖决策。本文填补了这方面的空白,提出了基于层次分析法的整数规划模型,通过该模型决策者可以评估运用反向拍卖技术是否是成本节约的和有效的。     

Teaching high school science using image processing: A case study of implementation of computer technology

An in-depth case study of teachers' use of image processing (a state-of-the-art computer technology used by research scientists) in biology, earth science, and physics classes within one high school science department explored issues surrounding technology implementation. The study, conducted within a districtwide, schoolwide, and classroom context, explored four areas related to the teacher's adoption of image processing: (a) teachers' background with computers outside of instructional use, (b) teachers' attitudes toward educational technology and insights gained from their experience using computers within the science curriculum, (c) training and perceived influence of district and school administrators, and (d) teachers' classroom and computer lab practices. The following factors were deemed critical in teachers' decision to use or not use image processing with their students: (a) time to thoroughly explore and master the technology so they could use it with students to explore science concepts; (b) classroom management skills specific to technology use; (c) perception of the teaching value of the technology; (d) perception of the reasonableness of administrators' expectations for technology use; and (e) understanding of how to implement inquiry-based science teaching, independent of technology issues. These factors have implications for how to help teachers use computer technology to teach high school science. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 297–327, 1998.     

Dynamic assessment and its potential for the assessment of reading competence

This article describes the approach of dynamic assessment, focusing on general approaches as well as specific constraints for the assessment of reading competence. Starting with an overview of the literature on dynamic assessments within educational research, the framework of dynamic assessment in which the current level of competence and (domain-specific) learning ability are assessed, is discussed with regards to its methodological and diagnostic implications.Reading competence is introduced as a domain in which interventions prove successful, and as a domain principally suitable for the assessment of learning ability. Furthermore, it is discussed whether elaborated feedback given within the procedure of reading competence assessment does uncover a learning ability which is specific to the domain of reading competence or not.     

Epistemological beliefs and epistemic strategies in self-regulated learning

How do epistemological attitudes and beliefs influence learning from text? We conceptualize epistemological attitudes and beliefs as components of metacognitive knowledge. As such, they serve an important function in regulating the use of epistemic strategies such as knowledge-based validation of information and checking arguments for internal consistency. We report results from two studies that investigated the effects epistemological attitudes and beliefs on the use of epistemic strategies in academic learning and the motivational states that mediate these effects. Study 1 (N = 289) tested a mediation model with epistemological attitudes (separate vs. connected knowing) and textual characteristics as distal predictors, and learning goals (learning factual knowledge vs. developing an own standpoint) as mediator variables. Separate knowing had large indirect effects on the use of epistemic strategies via the goal to develop an own point of view. In addition, learners adapted their learning goals and epistemic strategies depending on objective characteristics and the perceived familiarity of the texts they read. In Study 2 (N = 124), epistemological beliefs concerning the uncertainty of knowledge increased the use of epistemic strategies only when extrinsic study motivation was low. A mediated moderation model established this effect to be mediated by specific epistemic curiosity. These results illuminate the mechanisms of how epistemological attitudes and beliefs affect self-regulated learning. In contrast to other types of learning strategies, the use of epistemic strategies seems to be strongly and consistently linked to epistemological attitudes and beliefs.     

Does local dynamic stability of kayak paddling technique affect the sports performance? A pilot study

During competition, kayak athletes must optimally adapt to environmental factors (e.g. wind, waves) to achieve peak performance. However, the ability to adapt to such perturbations has never been assessed in kayak paddling. Therefore, the aim of the current study was to evaluate the local dynamic stability in sports technique of youth sprint kayak athletes. In a cross-sectional study, 14 healthy male athletes were recruited from an elite youth sprint kayak squad. During an incremental kayak ergometer test, mean power, heart rates and local dynamic technique stability of hands, arms, trunk and paddle were registered and the association with the athletes 2000?m free-water times were estimated using mixed models. The 2000?m free-water performance significantly predicted the paddles (p?=?.037) local dynamic stability whereas no association was found for the trunk or the upper extremity kinematics. In conclusion, kayak athletes with high-performance capability over 2000?m paddling depict high local dynamic technique stability. This emphasizes the importance of a stable technique for advanced kayak skills, especially regarding paddling movements.     

Anonymous body or first patient? A status report and needs assessment regarding the personalization of donors in dissection courses in German,Austrian, and Swiss Medical Schools

Many Anglo‐American universities have undertaken a paradigm shift in how the dissection of human material is approached, such that students are encouraged to learn about the lives of body donors, and to respectfully “personalize” them as human beings, rather than treating the specimens as anonymous cadavers. For the purposes of this study, this provision of limited personal information regarding the life of a body donor will be referred to as “personalization” of body donors. At this time, it is unknown whether this paradigm shift in the personalization of body donors can be translated into the German‐speaking world. A shift from donor anonymity to donor personalization could strengthen students' perception of the donor as a “first patient,” and thereby reinforce their ability to empathize with their future patients. Therefore, this study aimed to collect data about the current status of donation practices at German‐speaking anatomy departments (n = 44) and to describe the opinions of anatomy departments, students (n = 366), and donors (n = 227) about possible donor personalization in medical education. Anatomy departments in Germany, Austria, and Switzerland were invited to participate in an online questionnaire. One‐tenth of registered donors at Ulm University were randomly selected and received a questionnaire (20 items, yes‐no questions) by mail. Students at the University of Ulm were also surveyed at the end of the dissection course (31 items, six‐point Likert‐scale). The majority of students were interested in receiving additional information about their donors (78.1%). A majority of donors also supported the anonymous disclosure of information about their medical history (92.5%). However, this information is only available in about 28% of the departments surveyed and is communicated to the students only irregularly. Overall, 78% of anatomy departments were not in favor of undertaking donor personalization. The results appear to reflect traditional attitudes among anatomy departments. However, since students clearly preferred receiving additional donor information, and most donors expressed a willingness to provide this information, one could argue that a change in attitudes is necessary. To do so, official recommendations for a limited, anonymous personalization of donated cadaveric specimens might be necessary. Anat Sci Educ 11: 282–293. © 2017 American Association of Anatomists.     

Rahmenbedingungen männlichen Gerätturnens im deutschen Spitzensportsystem: Disziplinspezifische Anmerkungen zur nationalen Debatte

In German sports science, the national elite sport promotion system is a steady topic of discussions. The federal government and the German Olympic Sports Confederation (DOSB) expect new impetus of the reformed elite sport system in the areas of, inter alia, young athlete promotion, scientific support, and the coaches’ situation in German elite sport. The present article is a discipline-specific approach to these three issues for men’s artistic gymnastics. The first author served in various functions in German gymnastics (former squad athlete, young athletes‘ coach, academic teaching) for several years and is familiar with essential problems due to close communication with gymnasts, coaches, scientists, and officials. The purpose of this article is to point out specific challenges in men’s artistic gymnastics in view of the present debate on the German elite sport promotion system. This is intended to stimulate further discussions on solution approaches concerning the common exploitation of potentials.     

Improving near‐peer teaching quality in anatomy by educating teaching assistants: An example from Sweden

Peer‐assisted learning has gained momentum in a variety of disciplines, including medical education. In Gothenburg, Sweden, medical students who have finished their compulsory anatomy courses have the option of working as teaching assistants (TAs). Teaching assistants provide small group teaching sessions as a complement to lectures given by faculty. Previously, TAs were left to handle the role as junior teachers by themselves, but since 2011, a continuation course in anatomy has been developed with the aim of providing the TAs better anatomy knowledge and guidance for teaching. The course was designed to comprise 7.5 ECTS credits (equivalent to 5 weeks of full‐time studies), and today all TAs are required to take this course before undertaking their own teaching responsibilities. This study aims to compare course evaluations of TA teaching before and after the introduction of the anatomy continuation course, in order to understand how students perceived teaching performed by self‐learned versus trained TAs. The results of this study demonstrate that there was a trend towards better teaching performed by trained TAs. The variability in rankings decreased significantly after the introduction of the continuation course. This was mainly due to an improvement among the TAs with the lowest levels of performance. In addition to comparing student rankings, TAs were interviewed regarding their experiences and perceptions within the continuation course. The course was generally positively regarded. The TAs described a sense of cohesion and appreciation since the institute invested in a course dedicated specifically for them. Anat Sci Educ 11: 403–409. © 2018 American Association of Anatomists.     

Reflective analysis as a tool for task redesign: The case of prospective elementary teachers solving and posing fraction comparison problems

Mathematical task design has been a central focus of the mathematics education research community over the last few years. In this study, six university teacher educators from six different US institutions formed a community of practice to explore key aspects of task design (planning, implementing, reflecting, and modifying) in the context of comparing fractions using reasoning and sense-making. By presenting results of their implementation of two tasks with 63 prospective elementary teachers across three institutions and their reflective analysis of the implementation, the authors highlight the importance of collecting and analyzing data and reflecting on this analysis to inform the redesign of tasks. The authors also found that considering different types of tasks (problem solving vs. problem posing) helps illuminate different aspects of prospective elementary teachers' understanding, which can inform task redesign. Finally the authors contribute to the knowledge base on reasoning strategies for comparing fractions and prospective elementary teachers’ knowledge of these strategies.