Solving Hitchcock’s transportation problem by a genetic algorithm

IntroductionTheHitchcock’sTransportationProblem(HTP)canbeformulatedasaclassiclinearprogrammingprobleminwhichthesetofconstraintsisofaspecialstructure[1,2].TheHTPisapracticaltransportationprobleminproductiondistributionsector.Alotofpracticaltrans-portationandassignmentproblems,suchastheminimumcostroadnetworktrafficflowproblemwithsolidchargeinlogistics,canbeformulatedinthisway,anditisclearlythattheHTPmaybehasmorethanoneoptimalsolution.Itisveryimportantforadecision-makertoselectafavorableone…     

隐蔽在醒目处——教科书中的性别偏见

教科书是学生学习的主要媒介,隐蔽在教科书中的性别偏见是制约女性教育发展及教育性别平等的关键因素.本文综合了智利、格鲁吉亚、巴基斯坦和泰国的相关研究,分析了这些国家教科书性别偏见的背景、现状及共同特点,总结了这些国家教科书性别平等改革的进展、阻碍因素以及改革成功的必要条件和措施,并从教育决策者、教科书编制者和教师等角度对未来的性别平等教育改革提出了有效建议.     

Reward contrast in delay and probability discounting

In this study, we examined whether reward contrast influences choice between delayed and probabilistic outcomes. Specifically, we predicted that the subjective value of an intermediate reward would seem relatively larger or smaller, respectively, if it followed choices involving a smaller or larger reward and would produce corresponding changes in rates of delay and probability discounting. In Experiment 1, subjects made choices about hypothetical 5,000 or5,000 or 50 outcomes and then made choices about 500 outcomes. Delay-discounting rates for the500 outcomes. Delay-discounting rates for the 500 outcome were larger for Group 5,000 than for Group5,000 than for Group 50, whereas the opposite result was obtained for probability-discounting rates. In Experiment 2, we used a design that allowed for contrast effects to be assessed within subjects. Two groups made choices about delayed or probabilistic rewards. After completing question blocks in which the amount was 5,000 or5,000 or 50, subjects responded to questions with an intermediate amount (475/475/525). For Group Delay, the present value of the intermediate reward was greater after the 50 block than after the50 block than after the 5,000 block, whereas the opposite was obtained for Group Probability. The results from both experiments confirmed the predictions of reward contrast and suggested that the subjective value of a monetary reward varies inversely with the prior reward amount.     

A participatory approach to the identification of measures of number sense in children prior to school entry

The research reported in this paper used a modified Delphi procedure in an attempt to establish a consensus on tasks proposed to assess components of number sense identified as essential for early mathematics success by a broad range of academics with expertise in the area of early mathematics. Tasks included as measures of these components were based on assessment tasks developed by early mathematics researchers. Eighteen questionnaires were returned by academics from Australia, the UK, New Zealand, The Netherlands and the USA, all with published work in the areas of early mathematics and/or number sense. Both the proposed components and tasks in the questionnaires were limited to the number domain. The study revealed considerable agreement with a number of the proposed tasks and thus provided a way forward for the development of an early number sense assessment to be trialled with young children prior to their first year of formal schooling.     

Optimising the use of note-taking as an external cognitive aid for increasing learning

Taking notes is of uttermost importance in academic and commercial use and success. Different techniques for note-taking utilise different cognitive processes and strategies. This experimental study examined ways to enhance cognitive performance via different note-taking techniques. By comparing performances of traditional, linear style note-taking with alternative non-linear technique, we aimed to examine the efficiency and importance of different ways of taking notes. Twenty-six volunteer adult learners from an information management course participated in this study. Cognitive performance scores from a traditional linear note-taking group were compared with another group by using a commercially available non-linear note-taking technique. Both groups were tested in two settings: after a classroom lecture and a panel forum discussion. Tasks included measures on story comprehension, memory, complexity of mental representations and metacognitive skills. Data analysis revealed that the non-linear note-takers were significantly better than the linear group both in terms of the quantity and the quality of the learned material. This study demonstrates the importance of using cognitively compatible note-taking techniques. It identifies the cognitive mechanisms behind effective note-taking and knowledge representation. Using such techniques enables deeper understanding and more integrated knowledge management.     

List of Reviewers

The aim of this study was to investigate the effects of target distance on temporal and impact force parameters that are important performance factors in taekwondo kicks. Forty-nine taekwondo athletes (age = 24.5 ± 5.9 years; mass = 79.9 ± 10.8 kg) were recruited: 13 male experts, 21 male novices, 8 female experts, and 6 female novices. Impact force, reaction time, and execution time were computed. Three-way repeated measure ANOVAs revealed significant ‘distance’ effect on impact force, reaction time, and execution time (p = 0.001). Comparisons between distance conditions revealed that taekwondo athletes kicked with higher impact force from short distance (17.6 ± 7.5 N/kg) than from long distance (13.1 ± 5.7 N/kg) (p < 0.001), had lower reaction time from short distance (498 ± 90 ms) and normal distance (521 ± 111 ms) than from long distance (602 ± 121 ms) (p < 0.001), and had lower execution time from short distance (261 ± 69 ms/m) than from normal distance (306 ± 105 ms/m) or from long distance (350 ± 106 ms/m) (p = 0.003 and p < 0.001, respectively). In conclusion, target distance affected the kick performance; as distance increases, impact force decreased and reaction time increased. Therefore, when reaction to a simple visual stimulus is needed, kicking from a long distance is not recommended, as longer time is required to respond.     

Adult students,adult education,and the Ed.D.: An alternative residency experience

The increase of part-time adult students in Ed.D. programs calls into question the effectiveness and feasibility of the traditional, full-time residency. Adult education concepts provide a basis for designing an alternative residency which offers a quality academic and socialization experience. The Syracuse University alternative residency for the Ed.D. in Adult Education provides a model which can be adapted to other institutions and programs.Prior to joining the SU faculty, she had extensive experience as a postsecondary continuing education administrator. For almost three years she has been the Alternative Residency advisor for the Program's Ed.D. students.