Letters to the editor     

Douglas J. Besharov 《Child abuse & neglect》1981,5(1):61-65

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Einführungen in die Sportpsychologie     

Richard B. Aldermann  Alexander Thomas  Denis Glencross  H. Rieder 《Sportwissenschaft》1979,9(2):218-223

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Technical problems of international co-operative research projects     

Douglas Pidgeon 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1969,15(2):247-253

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Drawing Subway Maps: A?Survey     

Alexander Wolff 《Informatik - Forschung und Entwicklung》2007,22(1):23-44

This paper deals with automating the drawing of subway maps. There are two features of schematic subway maps that make them different from drawings of other networks such as flow charts or organigrams. First, most schematic subway maps use not only horizontal and vertical lines, but also diagonals. This gives more flexibility in the layout process, but it also makes the problem provably hard. Second, a subway map represents a network whose components have geographic locations that are roughly known to the users of such a map. This knowledge must be respected during the search for a clear layout of the network. For the sake of visual clarity the underlying geography may be distorted, but it must not be given up, otherwise map users will be hopelessly confused. In this paper we first give a rather generally accepted list of rules that should be adhered to by a good subway map. Next we survey three recent methods for drawing subway maps, analyze their performance with respect to the above rules, and compare the resulting maps among each other and to official subway maps drawn by graphic designers. We then focus on one of the methods, which is based on mixed-integer linear programming, a widely-used global optimization technique. This method guarantees to find a drawing that fulfills a subset of the above-mentioned rules (if such a drawing exists) and optimizes a weighted sum of costs that correspond to the remaining rules. The method can draw even large subway networks such as the London Underground in an aesthetically pleasing manner, similar to maps made by professional graphic designers. If station labels are included in the optimization process, so far only medium-size networks can be drawn. Finally we give evidence why drawing good subway maps is difficult (even without labels).  相似文献   

Measuring the contribution of biomedical research to the production of health     

Charles L. Vehorn  J.Steven Landefeld  Douglas P. Wagner 《Research Policy》1982,11(1):3-13

Technologically induced increases in health care costs have compelled policy-makers to ask hard budgetary questions about the value of biomedical research. Specific examples can be given to illustrate the returns from biomedical research on a disease-by-disease basis, but this information does not give a comprehensive enough perspective. The purpose of this paper is to estimate the historical contribution that biomedical research has made to the prolongation of life. Using a production function approach and various statistical models of the lag process, we estimate 23–48% of the decline in mortality over the 1930–1978 period can be attributed to biomedical research efforts. The lower bound estimate translates into a net return of $83 billion for our society, illustrating the past wisdom of investment in biomedical research. In recent years, however, the year-to-year decline in mortality rates has slowed, suggesting that mortality may not be an adequate output measure to justify expansion in research expenditures. Without alternative output measures, policy-makers and planners will have a difficult time in evaluating research benefits and making decisions on the allocation of future resources.  相似文献   

中亚造山带中斑岩铜钼矿的Re，Pt，Pd和Au含量     

Anita N．Berzina Alexander F．Korobeinikov 《中国科技期刊研究》2007,23(8):1957-1972

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An educational tv satellite for India: a critical assessment     

Alexander Melzer 《Research Policy》1976,5(2):158-178

The paper first presents the Indian proposal for an educational TV satellite with countrywide coverage (INSAT), and gives a sketch of the methodology applied in assessing this large-scale communications change in India. Efforts in communications planning should be considered from the point of view of their potential for helping large numbers of people to gain access to information (which is one aspect of the fact that half the Indian population lives in abject poverty). A first overview of the results according to such criteria demonstrates that the Indian proposal will be anything but a success. The satellite system cannot meet the needs of the broad population. On the one hand the project creates a large potential for mobilisation of the masses, on the other it is not in a position to transmit programmers, which in their content are to a minimal degree adapted to the needs of the adults. In the field of school broadcasts and teacher training, sufficient results are only reached by versions of the project which must be ruled out for political reasons. The capacity of the project is too restricted to avoid conflicts between individual states. Furthermore, the project benefits the largest language groups at the expense of the minorities.Some of the results are discussed in detail by way of a comparison of the impressive technical capacities of terms. Alternative projects with greater scope and with a decentralised structure (e.g. radio satellites or cassette systems) would be better than TV satellites, but pose problems of generating the information in suitable form. The bottleneck in communication is as much in the creation of differentiated information, as in the techniques of conveying it to the audiences. The final section discusses the background of the Indian interests in ‘educational satellites’.  相似文献   

Student self-concept and effort: gender and grade differences     

Alexander Seeshing Yeung 《教育心理学》2011,31(6):749-772

Students’ self-concept and effort in schoolwork are known to have significant influences on essential academic outcomes, but self-concept and effort may decline as students grow up. Students from 16 schools in Sydney (N?=?2200) were asked to rate on two self-concept components (competency and affect) and effort in schoolwork. Based on measures established in confirmatory factor analysis, a 5 (grade: 3rd, 5th, 7th, 9th, 11th) × 2 (gender: boys, girls) × 3 (measure: competency, affect, effort) repeated-measures ANOVA found that: (a) for all variables, scores were lower for higher grade levels; (b) boys were lower in affect and effort; (c) particularly for effort, gender differences favouring girls in primary became negligible in higher secondary; and (d) differences between primary and secondary tended to be greater for girls. Educators and curriculum designers need to consider the self-concept and effort of boys in the primary and girls in the secondary.  相似文献   

A Comparison of the Collaborative Scientific Argumentation Practices of Two High and Two Low Performing Groups     

Victor Sampson  Douglas B. Clark 《Research in Science Education》2011,41(1):63-97

This qualitative study examines the interactions between individuals, ideas, and materials as two high and two low performing groups of students engaged in a process of collaborative scientific argumentation. To engage students in collaborative scientific argumentation the students were randomly assigned to small groups of three students each. Each triad was asked to critique six alternative explanations for a discrepant event and to produce a single written argument justifying the explanation they felt was most valid or acceptable. The two higher performing triads produced arguments that included a sufficient and accurate explanation that was well supported with appropriate evidence and reasoning while the two lower performing triads produced arguments that included an inaccurate explanation supported by inappropriate justification. A verbal analysis of the interactive processes that took place within these four triads identified five distinct differences in the ways these triads engaged in collaborative scientific argumentation that seemed to promote or constrain the development of high quality written arguments. These differences include (1) the number of unique ideas introduced into the conversation, (2) how individuals responded to these ideas, (3) how often individuals challenged ideas when discussing them, (4) the criteria individuals used to distinguish between ideas, and (5) how group members used the available corpus of data. The conclusions and implications of this study include recommendations for the design and revision of curriculum, the development of new instructional models and technology-enhanced learning environments, and areas for future research.  相似文献   

The transition from education to employment in the context of stratification in Japan – a view from the outside     

Matthias Pilz  Peter‐Jörg Alexander 《比较教育学》2011,47(2):265-280

In many industrial nations, the processes of transition from education or training to employment are very important. Using Japan as a case study, this article considers these processes from an external perspective. The main criterion used is the issue of stratification within the education and training system. A detailed analysis of the transition process demonstrates that there is little differentiation between school students in Japan, making Japan's a very homogeneous education system by comparison with its international competitors. However, a type of indirect and/or informal stratification results from a ranking system for educational establishments and employers, reinforced by cooperation between individual educational establishments and specific employers.  相似文献