Adaptive retrieval practice with multiple-choice questions in the university classroom

Retrieval practice promotes retention more than restudying (i.e., the testing effect) and is applied to many educational settings. However, little research has investigated means to enhance this effect in educational settings. Theoretical accounts assume retrieval practice to be the most effective whenever retrieval is difficult but successful. Therefore, we developed a novel retrieval practice procedure, which adapts to learners' abilities and can be applied irrespective of learning content. This adaptive procedure aims to make retrieval gradually easier whenever students provide an incorrect answer. In a field experiment, students read book chapters as part of a weekly university course. In three consecutive weeks, they then practiced reading assignments by (a) adaptive testing, (b) non-adaptive testing and (c) restudy. In Week 4, a surprise criterial test took place. Restudy outperformed both testing conditions, whereas adaptive testing performed equally well as non-adaptive testing. However, exploratory analyses revealed that with increasing retention intervals, the superiority of restudy disappeared. Furthermore, whenever participants fully read the assignments and retention intervals increased, adaptive testing outperformed non-adaptive testing. In sum, adaptive retrieval practice did not prove to be generally superior, but retention interval and students' preparation for class might be conditions rendering adaptive retrieval useful in educational settings.     

化工大型机组的管理保养技术

化工机组设备的维护、保养和管理工作的在企业之中是非常重要的,只有提升企业管理、维护、保养机组的工作水平才能够让企业跟上时代发展的脚步。对化工机组设备维护管理的意义、维护保养的技术及其存在的问题和难点逐一进行介绍。     

竞技二打一游戏中同等牌力的研究

全国竞技二打一扑克锦标赛是国家体育总局棋牌运动管理中心推出的新兴项目，比赛采用复式赛赛制，然而这种赛制存在无法杜绝线上比赛作弊的问题，为此提出用同等牌力赛制来代替复式赛制进行比赛的设想。本文主要针对如何判定和选取具有同等牌力的初始手牌进行研究，提出用等级难度评估指标来计算初始手牌的难度，初始手牌难度相近的牌认定为同等牌力，并给出了同等牌力的选取方法；为保证一副牌所得等级难度评估指标的可靠性，提出用多个不同水平的“二打一AI程序”来代替真人打牌产生牌谱的方法。实验证明了同等牌力生成方法的有效性，本文提出的同等牌力方法应用于比赛是可行的。     

氨合成塔进出口换热器的制造技术难点

以某项目氨合成塔进出口换热器的制造过程为研究对象,阐明了此类设备的制造技术难点,包括换热管的质量控制、焊接、无损检测、热处理、管束组装等,并提出了对相关技术问题的解决方法和建议。     

Impact of sleep difficulty on single and repeated injuries in adolescents

Injuries are frequent and may be caused by sleep difficulty in youth. This study assessed the impact of sleep difficulty on single and repeated school and out-of-school injuries and the confounding role of socioeconomic factors and school, behaviour and health-related difficulties among adolescents. The study population included 1559 middle-school adolescents from north-eastern France (mean age 13.5, SD 1.3) who completed at the end of school year a self-administered questionnaire to gather school and out-of-school injuries during the school year, and to assess sleep difficulty and previous injury risk factors which were socioeconomic factors (family structure, parents’ education, father’s occupation, and family income), school performance, obesity, alcohol/tobacco/cannabis/hard drugs use, health status, psychological health, and involvement-in-violence. For sleep difficulty and behaviour and health-related difficulties their first occurring over adolescent’s life course was gathered. Multinomial logistic regression models were used retaining only sleep difficulty and other risk factors which had started before the school year (thus before the injuries studied). School and out-of-school injuries and sleep difficulty were frequent. The adolescents with sleep difficulty without medical treatment had a higher risk of single school and out-of-school injuries (gender–age-adjusted odds ratio gaOR 1.86 and 1.76, respectively) and a much higher risk of repeated school and out-of-school injuries (≥2 injuries; gaOR 2.43 and 3.73, respectively). The adolescents with persistent sleep difficulty despite a medical treatment also had a higher risk of single school and out-of-school injury (gaOR 2.31 and 1.78, respectively), and a much higher risk of repeated school and out-of-school injuries (gaOR 4.92 and 4.36, respectively). Socioeconomic factors had a moderate contribution (<27%) while school, behaviour and health-related difficulties had a high contribution (reaching 71%) to the association between sleep difficulty and single/repeated injuries. The role of these factors differed between single/repeated school/out-of-school injuries. Injury prevention should focus on screening and monitoring sleep difficulty and previous difficulties, especially among adolescents with socioeconomic difficulties, via physician–parent–school–adolescent collaborations.     

140dam3/h制氢装置开工难点与对策

讨论了某公司140 dam3/h制氢装置首次开工过程中遇到的开工难点和对策.装置采用轻烃蒸汽转化制氢技术,由于规模大,开工时系统吹扫、气密、机泵试运等过程有一定困难.通过改造,解决了鼓风机、引风机入口蝶阀不能正常开关等问题,加装轴流风机和百叶窗,降低了转化炉顶环境温度,从界区外倒引中压蒸汽提高了清洁蒸汽汽包煮炉压力,在原料精制部分增加开工氮气线,解决了系统长循环流量不足问题.装置一次开车成功说明采取措施是正确的,开工正常后各项运行参数均处于合理范围,装置运行初期每吨氢气加工能耗47.86 GJ,低于设计值.     

Task difficulty and team diversity on team creativity: Multi-agent simulation approach

Organizational structures are complex and vary according to sector, field, and type of business or service. In order to be effective, an organization needs to tailor its activities to the environment in which is it located. Based on contingency perspectives, this study is focused on investigating effective ways to design team diversity and maximize team creativity according to task difficulty levels. Considering the organizational team member as an agent, the study employed a multi-agent simulation method to understand the progress of creative manifestation, by observing the exploration and exploitation activity of team members over certain periods of time. The results first reveal that the level of team diversity influences the amount of creativity manifested by team members’ activities, such as exploration and exploitation. Second, managers have to properly facilitate either exploration or exploitation depending on task difficulty by striking a balance between them.     

Easily too difficult: Estimating item difficulty in computer simulated microworlds

Dealing with complexity and dynamics is increasingly becoming part of people's everyday lives. The necessity of dealing with complex systems has instigated the use of computer simulations, so-called microworlds (MWs), to assess and study human behavior in complex situations. Although these MWs enjoy great popularity with both practitioners and researchers, their psychometric qualities have been questioned, and studies that have investigated these qualities have been sparse. In particular, only a few studies have investigated the factors that contribute to item difficulty in MWs. To fill this gap, we analyzed data from 3128 Finnish students with a linear logistic test model. Our results suggest that item difficulty in MWs can be almost perfectly predicted by six basic item characteristics, namely, (a) the use and number of eigendynamics, the numbers of (b) input and (c) output variables, the numbers of (d) input and (e) output variables not related to any other variables, and (f) the total number of relations between all variables. In addition, we provide evidence for the necessity of differentiating between the difficulty of controlling an MW (knowledge application) and understanding its underlying structure (knowledge acquisition). Finally, we discuss further theoretical and practical implications of an increased understanding of MWs for their use as assessment instruments.