航天型号费用估算随机不确定性的优化综合   总被引：2，自引：0，他引：2  

李德光  张明立  胡运权 《预测》2000,19(2):49-51

本文论术字复杂的技术和外界环境条件下,三遇用估算方法涉及到的随机不确定性及其表征参数－标准差,通过采用最小线性方差组合,实现了三种费用估算方法随机不确定性的优化综合,对方法之间存在非零协方差的情况。本文也给出了相应的求解方法。  相似文献   

Lipid peroxidation and spectrin of RBC membrane in hydroxyurea treated Eβ thalassaemia     

Manisha De  N. Banerjee  G. Talukdar  D. K. Bhattacharya 《Indian journal of clinical biochemistry : IJCB》2000,15(1):56-59

The aim of the present work is to understand the effect of low dose of hydroxyurea (HU) therapy on oxidative damage of RBC membrane in non-transfused Eβ thalassaemia. HU was administered at a dose of 30 mg/kg/day for 90 consecutive days. The percentage of spectrin and the level of malondialdehyde (MDA), fetal hemoglobin (HbF), hemoglobin (Hb) and packed cell volume (PCV) were measured. The HbF level was significantly increased after 90 days of HU therapy. MDA level of RBC membrane was decreased. There was no change in PCV, Hb and spectrin content of RBC membrane after HU therapy for 90 days in Eβ thalassaemia. Increment of HbF in HU treated Eβ patient may have some role on the correction of oxidative damage of RBC membrane by inhibiting further degradation of spectrin and by decreasing lipid peroxidation of red cell membrane.  相似文献   

我国农业资源法制建设问题探讨     

张德永 《资源科学》1998,20(3):6-11

农业资源　法是我国资源法体系的重要组成部分。当前,农业资源立法采取的是以自然资源构成要素为法律调整对象的立法模式,主要确立了权属、调查评价、规划、保护和许可审批制度,仍处于单项法律、法规为主的群法状态。法制体系不健全、内容不完善、与市场经济的经济运行机制农业资源、法律制度  相似文献   

Relating students' reasoning to the history of science: The case of chemical equilibrium   总被引：1，自引：0，他引：1  

Jan H. Van Driel  Wobbe De Vos  Nico Verloop 《Research in Science Education》1998,28(2):187-198

In this study, the reasoning of students, who are introduced to the concept of chemical equilibrium, was related to the historical development of this concept. In the first stage of the study, remarkable similarities were observed between students' reasoning on the issue of incomplete chemical conversions and the reasoning of 19th-century scientists, especially when molecular notions were included. In the next stage of the study, some authentic problems and questions, that were essential in the historical development of chemical equilibrium, were presented to students. It appeared that they recognised the significance of these problems and questions. Moreover, most students were eager to find explanations. Students, reasoning in molecular terms, would sometimes explain these problems in terms similar to historical explanations. Other students, however, suggested explanations in non-molecular terms, which, although chemically valid, did not appear to have historical antecedents. It was concluded that the study of authentic historical sources may inspire the design of effective teaching activities.  相似文献   

以医学科研人员为中心实施感动服务的探讨     

刘燕清  陈德 《科技管理研究》2005,25(7):53-54

医疗机构的改革必然对医院科研管理人员提出更高的要求,本文提出以医学科研人员为中心、以感动服务为基点的全新服务意识和服务方式。医院科研管理人员必须树立“甘为他人作嫁衣”的无私奉献精神,转变服务观念,提供感动服务,并通过不断学习,提高自身素质,在服务中不断创新,更好地为医院科研服务。  相似文献   

A packaged intervention to reduce disruptive behaviors in general education students     

Diane De Martini‐Scully  Melissa A. Bray  Thomas J. Kehle 《Psychology in the schools》2000,37(2):149-156

This investigation employed a combination multiple baseline/reversal design across individuals to examine the effects of a packaged intervention designed to reduce disruptive behaviors in two 8‐year‐old female students, with a third 8‐year‐old female student serving as a control. The intervention was delivered through a contingency contract and was comprised of precision requests, antecedent strategies (i.e., public posting of classroom rules, and teacher movement), positive reinforcement (i.e., mystery motivators, token economy), and the reductive technique of response cost.During baseline, the percentage of intervals that the students evidenced disruptive behaviors averaged 41%. This was reduced to an average of 20% during treatment. In the withdrawal phase, disruptive intervals increased to an average of 25%. Reinstatement of the intervention resulted in a further reduction of disruptive intervals of 20%. © 2000 John Wiley & Sons, Inc.  相似文献   

Attitudes of Secondary School STEM Teachers towards Supervising Research and Design Activities     

Vossen  T. E.  Henze  I.  Rippe  R. C. A.  Van Driel  J. H.  De Vries  M. J. 《Research in Science Education》2019,51(2):891-911

Research and design activities are important focus points in international policies for secondary Science, Technology, Engineering and Mathematics (STEM) education. It is up to school teachers to implement and supervise these activities in the STEM classroom. However, not much is known about the attitudes teachers hold towards supervising research projects or design projects. In this study, a questionnaire to measure teacher attitudes towards supervising research activities and design activities in secondary school was completed by 130 Dutch teachers who taught the relatively new Dutch STEM subjects O&O (research and design) and NLT (nature, life, and technology). These integrated STEM subjects are project and context based and are taught in a limited number of schools. Important differences between these integrated STEM subjects are their student and teacher populations: NLT is taught in grades 10–12 by teachers with a qualification in a science subject, while O&O is taught in grades 7–12 and can be given by any teacher in secondary school. The results showed that on average, both O&O and NLT teachers had high self-efficacy scores on supervising research and design projects even when they had received no special education in doing so. Furthermore, the teachers in general viewed supervising research projects as a more relevant activity than supervising design. Since research and design activities are becoming more important in (inter)national curriculum standards, STEM teacher education and subsequent professional development should not only familiarize teachers with supervising research projects, but with design projects as well.

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Schoolteachers,social control and professional conflict: government procedures brought against schoolteachers in Galicia (1859–1910)     

Narciso De Gabriel 《History of education》2018,47(4):466-487

This article aims to analyse the disciplinary procedures brought against public schoolteachers in Galicia from 1859 until 1910. The article starts with the presentation of the legal basis for the government inquiries and the administrative framework in which they were implemented. Following is an examination of the evolution of the inquiries, the origin of the complaints, the charges filed against the teachers and the sanctions proposed. Lastly some examples are provided of the most widespread offences, consisting of abandonment of teaching as well as other charges of moral misconduct such as cohabitation and sexual abuse of the children.  相似文献   

Metacognitive awareness as measured by second-order judgements among university and secondary school students     

Nederhand  Marloes L.  Tabbers  Huib K.  De Bruin  Anique B.H.  Rikers  Remy M. J. P. 《Metacognition and Learning》2021,16(1):1-14

Metacognition and Learning - When compared to high performers, low performers generally have more difficulty to accurately estimate their own performance. This has been explained by low performers...  相似文献   

Human resources for Big Data professions: A systematic classification of job roles and required skill sets     

Andrea De Mauro  Marco Greco  Michele Grimaldi  Paavo Ritala 《Information processing & management》2018,54(5):807-817

The rapid expansion of Big Data Analytics is forcing companies to rethink their Human Resource (HR) needs. However, at the same time, it is unclear which types of job roles and skills constitute this area. To this end, this study pursues to drive clarity across the heterogeneous nature of skills required in Big Data professions, by analyzing a large amount of real-world job posts published online. More precisely we: 1) identify four Big Data ‘job families’; 2) recognize nine homogeneous groups of Big Data skills (skill sets) that are being demanded by companies; 3) characterize each job family with the appropriate level of competence required within each Big Data skill set. We propose a novel, semi-automated, fully replicable, analytical methodology based on a combination of machine learning algorithms and expert judgement. Our analysis leverages a significant amount of online job posts, obtained through web scraping, to generate an intelligible classification of job roles and skill sets. The results can support business leaders and HR managers in establishing clear strategies for the acquisition and the development of the right skills needed to leverage Big Data at best. Moreover, the structured classification of job families and skill sets will help establish a common dictionary to be used by HR recruiters and education providers, so that supply and demand can more effectively meet in the job marketplace.  相似文献