共查询到20条相似文献，搜索用时 15 毫秒
1.
Korean middle school students are experiencing high rates of behavioral and emotional problems, suggesting a need for comprehensive screening instruments with strong psychometric properties in school settings. The present study investigated the utility of the Behavior Assessment System for Children‐2 Self‐Report of Personality, Adolescent Form (BASC‐2 SRP‐A) to assess clinical problems and adaptive strengths among Korean middle school students. For this revalidation study of the BASC‐2, we first translated the BASC‐2 SRP‐A into Korean (K‐BASC‐2 SRP‐A). Then, using a total of 458 Korean middle school students aged 12 to 15 years, we examined the factor structure and reliability of the clinical, adaptive, and composite scale scores of the K‐BASC‐2 SRP‐A. We also used a separate sample of 45 middle school students to examine the convergent validity of a subset of the K‐BASC‐2 SRP‐A scales targeting the common problem areas of anxiety, depression, and inattention. Based on the current results, we found strong psychometric properties of the K‐BASC‐2 SRP‐A for use among adolescents in Korea, including a well‐fitting factor structure consistent with the originally proposed model, adequate reliability estimates, and validity coefficients falling in the acceptable range. The K‐BASC‐2 SRP‐A can offer the Korean school mental health field a useful and much‐needed multidimensional screening measure for middle school youths. 相似文献
2.
Research on cubic polynomial acceleration and deceleration control model for high speed NC machining
Hong-bin LENG Yi-jie WU Xiao-hong PAN 《浙江大学学报(A卷英文版)》2008,9(3):358-365
To satisfy the need of high speed NC （numerical control） machining, an acceleration and deceleration （acc/dec） control model is proposed, and the speed curve is also constructed by the cubic polynomial. The proposed control model provides continuity of acceleration, which avoids the intense vibration in high speed NC machining. Based on the discrete characteristic of the data sampling interpolation, the acc/dec control discrete mathematical model is also set up and the discrete expression of the theoretical deceleration length is obtained furthermore. Aiming at the question of hardly predetermining the deceleration point in acc/dec control before interpolation, the adaptive acc/dec control algorithm is deduced from the expressions of the theoretical deceleration length. The experimental result proves that the acc/dec control model has the characteristic of easy implementation, stable movement and low impact. The model has been applied in multi-axes high speed micro fabrication machining successfully. 相似文献
3.
基于多孔介质渗流力学理论建立了垃圾填埋气体传输过程的动力学模型,采用Laplace变换对气体传输渗流场控制方程进行近似解析求解,得到了填埋气体非线性渗流的压力分布规律.由不同时间填埋气体压力随水平距离分布计算结果看出:随时间的增长,压力曲线变缓,压力增大. 相似文献
4.
We proposed a novel impact pneumatic cylinder with a reservoir connected to the inlet chamber so that the pneumatic cylinder can achieve a high speed. A reservoir with high-pressure air enabled the cylirider to achieve considerable＇acceleration when it began to Work. We established a mathematical model to simulate the behaviors of an impact pneumatic cylinder, focusing on the relationships of the maximum piston speed with the air supply pressure and the reservoir volume. The results show that the reservoir .can help significantly enhance the pneumatic system velocity. When the reservoir volume is less than double the cylinder volume, an increase in the reservoir volume is more effective in increasing the maximum piston velocity. 相似文献
5.
全球化条件下发展中国家开放收益与成本的模型分析 总被引：2，自引：0，他引：2
陈铭 《华东师范大学学报(哲学社会科学版)》2001,33(1):80-88
发展中国家在经济全球化条件下的对外开放的收益成本，可以通过建立数学模型加以量化分析，运用这一模型对20世纪80年代以来的有关数据进行实证检验。可以得出结论：中国目前尚未达到最佳开放度，在新的世纪里，时一步提高中国对外开放度，开放收益的增长速度将超过开放成本的增长速度，从而进一步扩大对外开放将能够提高我国的开放净收益，因此，在新世纪中国对外开放应采取以国际竞争力为导向的均衡型开放战略。 相似文献
6.
To reduce the high repetition rates in early years of primary school, the government of Cambodia piloted a school readiness program (SRP) in the first two months of Grade 1 of primary school. This study examines whether such intervention has effects on students’ immediate acquisition of school readiness skills as well as students’ longer term achievement of formal curriculum. The study finds that children who participated in SRP outperform children that did not participate in both outcomes, controlling for pretest score and background variables. The findings suggest that the intervention may be one alternative model to preschools in countries where access to pre-primary education is limited. 相似文献
7.
Influences affecting the soil-water characteristic curve 总被引：2，自引：0，他引：2
INTRODUCTION The soil-water characteristic curve (SWCC) gives the relationship between the amount of water in the soil (i.e. gravimetric or volumetric water content) and soil suction (i.e. matric suction at low suction and total suction at high suction). Many properties of a partially saturated soil such as the coefficient of permeability, shear strength and volume strain, pore size distribution, the amount of water contained in the pores at any suction, can be obtained from the SWCC. … 相似文献
8.
提出一种基于长短期神经网络的深度学习预测模型,依托现场数据对土仓压力进行预测。结果表明,在5个可控因素的基础上,增加与土仓压力具有相关关系的不可控因素作为输入,评价指标平均绝对误差、均方误差分别降低了0.901%、0.021%,校正后的决定系数提高了16%,为土仓压力的精准预测和设定提供了借鉴。 相似文献
9.
This paper describes the effects of fire on durability of reinforced concrete structures, and points out that fire not only damages the chemical composition and physical structure of concrete by high temperature, but also leads to an additional risk due to the generation of polyvinyl chloride (PVC) combustion gases. A mathematical model is proposed to calculate chloride ingress profiles in fire damaged concrete, so as to explore the service life prediction of the structure. Rapid Chloride Migration (RCM) test was carried out to determine the chloride diffusion coefficients for the application of the mathematical model. Finally, the detected results of a reported case testified to the validity of the mathematical model. 相似文献
10.
Marilyn A. Winkleby Judith Ned David Ahn Alana Koehler Kathleen Fagliano Casey Crump 《Journal of Science Education and Technology》2014,23(1):138-144
Given limited funding for school-based science education, non-school-based programs have been developed at colleges and universities to increase the number of students entering science- and health-related careers and address critical workforce needs. However, few evaluations of such programs have been conducted. We report the design and methods of a controlled trial to evaluate the Stanford Medical Youth Science Program’s Summer Residential Program (SRP), a 25-year-old university-based biomedical pipeline program. This 5-year matched cohort study uses an annual survey to assess educational and career outcomes among four cohorts of students who participate in the SRP and a matched comparison group of applicants who were not chosen to participate in the SRP. Matching on sociodemographic and academic background allows control for potential confounding. This design enables the testing of whether the SRP has an independent effect on educational- and career-related outcomes above and beyond the effects of other factors such as gender, ethnicity, socioeconomic background, and pre-intervention academic preparation. The results will help determine which curriculum components contribute most to successful outcomes and which students benefit most. After 4 years of follow-up, the results demonstrate high response rates from SRP participants and the comparison group with completion rates near 90 %, similar response rates by gender and ethnicity, and little attrition with each additional year of follow-up. This design and methods can potentially be replicated to evaluate and improve other biomedical pipeline programs, which are increasingly important for equipping more students for science- and health-related careers. 相似文献
11.
JIN Wei-liang ZHANG Yi 《浙江大学学报(A卷英文版)》2007,8(5):675-681
This paper describes the effects of fire on durability of reinforced concrete structures, and points out that fire not only damages the chemical composition and physical structure of concrete by high temperature, but also leads to an additional risk due to the generation ofpolyvinyl chloride （PVC） combustion gases. A mathematical model is proposed to calculate chloride ingress profiles in fire damaged concrete, so as to explore the service life prediction of the structure. Rapid Chloride Migration （RCM） test was carried out to determine the chloride diffusion coefficients for the application of the mathematical model. Finally, the detected results of a reported case testified to the validity of the mathematical model. 相似文献
12.
通过对电除尘器工作原理的分析,建立了电除尘器高压电源供电数学模型。以这些数学模型为基础,采用免疫遗传算法对电除尘器高压电源进行优化控制的仿真研究。仿真结果表明,只要合理调节各级电场的工作电压、尽量减少无效电流和低效电流的发生机会,可使电除尘器高压电源的控制性能达到最佳状态。 相似文献
13.
姚程宽 《四川教育学院学报》2014,(3):118-121
Vapnik等人在统计学习理论和结构风险最小化的基础上提出了支持向量机算法（SVM）。该算法在高维模式识别、非线性、小样本等方面有较好的性能,已在许多领域取得了成功的应用。双正则化参数支持向量机的出现,更进一步提高了对于两类问题的研究成果。而利用样本数量来调整两个正则化参数C＋和C-的比值,这一方法也得到了较为广泛的应用和认可,特另13是在两类数据集中,即使这一理论没有经过严格的数学证明。文章以USPS数据库为基础,对之进行了大量的仿真实验,结果表明这个被广为接受的观点是不成立的。 相似文献
14.
根据高炉TRT工艺和影响高炉顶压稳定的因素,以及对高炉TRT系统的管路分析,建立高炉顶压TRT系统数学模型。应用Matlab对静叶单独调节高炉顶压时系统的数学模型进行仿真验证,为进一步改善高炉顶压的稳定提供理论依据。 相似文献
15.
Cover systems are used to prevent water infiltration into a waste body. They also play an important role in controlling landfill gas transport from the waste body to the atmosphere. It is important to assess the flux of landfill gas at the surface of a cover system by considering the coupled effects of rainwater infiltration and gas transport in the cover soils. We have developed a 1D mathematical model for coupled transient gas and water transport in unsaturated cover soils. The coupled model was solved by the finite element method. Results obtained by the proposed model agreed well with experimental data. Based on the proposed solution, the influences of gas pressure, gas permeability, and the thickness of the cover soils on soil gas concentration profiles were investigated. The difference in soil gas concentration reached up to 31% as the thickness of cover increased from 1 to 2 m. Gas concentration at a depth of 0.2 m decreased by 6% as the amplitude of atmospheric gas pressure fluctuation increased from 20 to 100 Pa. The gas concentration increased by only 3% when gas permeability increased by a factor of 2 for a relatively long period of gas migration (e.g., 60 h) under the given conditions. Results suggest that both diffusion and advection should be considered when estimating gas transport in unsaturated cover soils. The numerical model can be used in the design of cover systems in relation to gas breakthrough time, breakthrough concentration, and flux. 相似文献
16.
Hélia Jacinto Susana Carreira 《International Journal of Science and Mathematics Education》2017,15(6):1115-1136
This study offers a view on students’ technology-based problem solving activity through the lens of a theoretical model which accounts for the relationship between mathematical and technological knowledge in successful problem solving. This study takes a qualitative approach building on the work of a 13-year-old girl as an exemplary case of the nature of young students’ spontaneous mathematical problem solving with technology. The empirical data comprise digital records of her approaches to two problems from a web-based mathematical competition where she resorted to GeoGebra and an interview where she explains and describes her usual problem solving activity with this tool. Based on a proposed model for describing the processes of mathematical problem solving with technologies (MPST), the main results show that this student’s solving and expressing the solution are held from the early and continuing interplay between mathematical skills and the perception of the affordances of the tool. The analytical model offers a clear picture of the type of actions that lead to the solution of each problem, revealing the student’s ability to deal with mathematics and technology in problem solving. By acknowledging this as a case of a human-with-media in solving mathematical problems, the students’ efficient way of merging technological and mathematical knowledge is portrayed in terms of her techno-mathematical fluency. 相似文献
17.
Chris Hurst 《Educational research; a review for teachers and all concerned with progress in education》2017,59(1):107-123
Background: Teacher knowledge continues to be a topic of debate in Australasia and in other parts of the world. There have been many attempts by mathematics educators and researchers to define the knowledge needed by teachers to teach mathematics effectively. A plethora of terms, such as mathematical content knowledge, pedagogical content knowledge, horizon content knowledge and specialised content knowledge, have been used to describe aspects of such knowledge.Purpose: This paper proposes a model for teacher knowledge in mathematics that embraces and develops aspects of earlier models. It focuses on the notions of contingent knowledge and the connectedness of ‘big ideas’ of mathematics to enact what is described as ‘powerful teaching’. It involves the teacher’s ability to set up and provoke contingent moments to extend children’s mathematical horizons. The model proposed here considers the various cognitive and affective components and domains that teachers may require to enact ‘powerful teaching’. The intention is to validate the proposed model empirically during a future stage of research.Sources of evidence: Contingency is described in Rowland’s Knowledge Quartet as the ability to respond to children’s questions, misconceptions and actions and to be able to deviate from a teaching plan as needed. The notion of ‘horizon content knowledge’ (Ball et al.) is a key aspect of the proposed model and has provoked a discussion in this article about students’ mathematical horizons and what these might comprise. Together with a deep mathematical content knowledge and a sensibility for students and their mathematical horizons, these ideas form the foundations of the proposed model.Main argument: It follows that a deeper level of knowledge might enable a teacher to respond better and to plan and anticipate contingent moments. By taking this further and considering teacher knowledge as ‘dynamic’, this paper suggests that instead of responding to contingent events, ‘powerful teaching’ is about provoking contingent events. This necessarily requires a broad, connected content knowledge based on ‘big mathematical ideas’, a sound knowledge of pedagogies and an understanding of common misconceptions in order to be able to engineer contingent moments.Conclusions: In order to place genuine problem-solving at the heart of learning, this paper argues for the idea of planning for contingent events, provoking them and ‘setting them up’. The proposed model attempts to represent that process. It is anticipated that the new model will become the framework for an empirical research project, as it undergoes a validation process involving a sample of primary teachers. 相似文献
18.
基于加热表面核化点遵循泊松与分形分布,提出了临界热流密度的一个数学模型,从该模型中发现大空间临界热流密度(CHF)是壁面过热度、接触角和流体物理特性的函数.对不同的接触角,模型预测的结果与实验数据进行了比较.两者很好地吻合. 相似文献
19.
The purpose of mathematical models in any discipline is to describe accurately the relationships among significant variables of a system. The use of mathematical models is widespread in the sciences, but has rarely found its way into educational research. In developing a mathematical model for mastery learning, empirical research has shown that prior learning, motivation, and time on task are part of the significant variables that work together in some way in a determination of student achievement. A mathematical model that shows the relationship among these variables has been developed. To test the appropriateness of this mathematical model, carefully designed and controlled experiments must be conducted to collect numerical data on the significant variables. Using the model, the accuracy of its predictions can be compared with actual results. This is the technique used in testing mathematical models in the sciences and should be applicable to mathematical models of learning. 相似文献
20.
为研究高中生对数学模型思想的了解睛况,以及实际运用能力,通过问卷调查统计、SPSS软件分析得出目前中学生对于数学模型思想了解还不够深,学生对数学模型思想了解程度与解决问题的建模能力之间具有高度的相关性。 相似文献