线性分式规划的Frank—wolfe优化算法

线性分式规划在经济管理领域有着广泛的应用,但分式规划是非线性优化模型,相对复杂。利用Frank-wolfe优化方法,将带有线性约束条件的一类线性分式规划转化为线性规划,求得此类线性分式规划的局部最优解;同时给出了算法的步骤,讨论了收敛性定理;通过数值实验,发现该算法具有迭代次数少等优点。     

Sharing practices,but what is the story? Exploring award-winning teachers’ conceptions of teaching

This paper critically considers the attempt by a research-intensive university in Asia to draw on and make public the practices of teaching award winners in different disciplines through the use of narrative vignettes. More specifically, this paper examines what the vignettes suggest about the connection between award-winning teachers’ conceptions of teaching (CT) on the one hand, and scholarly investigations of practice on the other, and to what extent the vignettes meet the aim of using the scholarship of teaching and learning as an instrument of effective academic development. Content analysis of the vignettes revealed that award-winning teachers’ CT tend to focus predominantly on enhancing learning, followed by encouraging collective knowledge creation and transmission of knowledge. A two-dimensional framework was also used to analyse the vignettes along a tacit-integrated continuum and within an intuitive-reflective frame of inquiry. The findings are discussed in relation to teachers’ perception of their impact on students’ learning and ways to enhance their own practice, with implications for teaching awards, documentation, and dissemination of high-level teaching achievement.     

Stakeholders’ perceptions and recommendations of a high school leadership development programme for athletes in Singapore

ABSTRACT

This study examined the perceptions of key stakeholders of a high school athlete leadership development training programme. Participants included 36 athletes (males = 23, females = 13) from two team sports (rugby n = 11 and volleyball n = 6) and two individual sports (bowling n = 8 and table tennis n = 11), as well as four coaches representing each of these sports and four teachers. Individual interviews were conducted for coaches, teachers, and athlete leaders, while athletes took part in focus group interviews. Inductive thematic analysis was used to analyse all data sets. Results showed that the athlete leadership programme developed qualities such as responsibility, role modelling, motivation, communication, perseverance, and team unity that would help athlete leaders perform their roles and responsibilities. The results also highlighted some limitations including earlier involvement from key stakeholders, tailored training for athlete leaders, and a more effective transfer of learning.     

Hierarchical Mentoring: A Transformative Strategy for Improving Diversity and Retention in Undergraduate STEM Disciplines

In the United States, less than half of the students who enter into science, technology, engineering, and mathematics (STEM) undergraduate curricula as freshmen will actually graduate with a STEM degree. There is even greater disparity in the national STEM graduation rates of students from underrepresented groups with approximately three-fourths of minority students leaving STEM disciplines at the undergraduate level. A host of programs have been designed and implemented to model best practices in retaining students in STEM disciplines. The Howard Hughes Medical Institute (HHMI) Professors Program at Louisiana State University, under leadership of HHMI Professor Isiah M. Warner, represents one of these programs and reports on a mentoring model that addresses the key factors that impact STEM student attrition at the undergraduate level. By integrating mentoring and strategic academic interventions into a structured research program, an innovative model has been developed to guide STEM undergraduate majors in adopting the metacognitive strategies that allow them to excel in their programs of study, as they learn to appreciate and understand science more completely. Comparisons of the persistence of participants and nonparticipants in STEM curricular, at the host university and with other national universities and colleges, show the impact of the model’s salient features on improving STEM retention through graduation for all students, particularly those from underrepresented groups.     

Using a Dialogical Approach to Examine Peer Feedback During Chemistry Investigative Task Discussion

Peer feedback is an inherent feature of classroom collaborative learning. Students invariably turn to their peers for feedback when carrying out an investigative task, and this feedback is usually implicit, unstructured and may positively or negatively influence students’ learning when they work on a task. This study explored the characteristics of verbal peer feedback during a collaborative investigative chemistry task involving New Zealand Year 13 students. During the planning stage of the students’ investigation, the discussions of five pairs of students were recorded and then transcribed. Analysis of transcribed verbal data focused on interactions that involved peer feedback along two dimensions, interactive/non-interactive and dialogic/authoritative (Mortimer and Scott, 2003). The findings indicated that although students adopted a predominantly interactive/authoritative communicative approach, with peer feedback as confirmation or evaluation, they are also capable of a more interactive/dialogic exchange, characterised by elaborative peer feedback. We discuss how this dialogic perspective on peer feedback provides an alternative approach to the analysis and study of student–student interactions during science investigations. The findings should be interpreted in light of the limitations in terms of sample size, grouping and specificity of the coding scheme. Implications for teacher practice are discussed in relation to facilitating peer feedback discourse in the science classroom.     

E家之言:热爱平凡、享受快乐、诚实研究

图书馆员是一份非常平凡的工作，平凡到可以被人忽略。前些日子，一个网名叫“土匪”的图书馆学系在校生写了一篇向新生介绍图书馆学的帖子，我高度评价这个学生对图书馆事业的热爱。但是在这个帖子里，他努力想证明研究图书馆学和从事图书馆工作也能出人头地，我不赞成他的看法。毕竟能够成为国家主席、总统夫人的图书馆员只有那么几个。大部分的图书馆员是默默无闻的。作为一个图书馆员，热爱平凡是其最重要的人格品质。一个人什么叫出人头地？有些地方人口众多，资源有限，大家都想出人头地，所以竞争就激烈，争来争去，当老年静下来的时候，回头一想，发现一生只有勾心斗角了，发现其实一生没有快乐过，没有轻松过，那时才后悔莫及。其实，人生最大的乐趣不是出人头地，而是享受人生的快乐。     

我国银行监管的问题分析及对策研究

我国银行业监管发展的历史较短,再者监管问题与政治、经济和金融体制紧密相关,这使得建立起一个健全、高效、规范化的银行监管体系具有一定的复杂性和艰巨性.由于建立完善监管体制,提高监管效率,能够最大程度地保护广大存款人利益,维护银行业稳定,因此,其将成为监管部门面临的一个紧迫而又关键的课题.在此背景下,本文对我国银行监管的现状及存在的问题进行分析,为完善我国银行监管体系提出了建议.     

Physical environment as a 3-D textbook: design and development of a prototype

The use of the physical environment as a three-dimensional (3-D) textbook is not a common practice in educational facilities design. Previous researches documented that little progress has been made to incorporate environmental education (EE) into architecture, especially among the conventional designers who are often constrained by the budget and building area requirements. This article presents an exploratory project to develop a prototype for the 3-D textbook. The author does not formulate ideas and concept based on the pre-determined specs in a design brief. Instead, the design solution evolved through a qualitative case study conducted at the Green School in Bali, Indonesia. Data were collected through a series of interviews and on-site observations. The qualitative findings uncovered four design features for the 3-D textbook. A prototype was subsequently developed using the design features as a blueprint. The prototype serves as a testing ground for new ideas as well as a platform to promote awareness and acceptance of the 3-D textbook among the practitioners. Consequently, this article attempted a significant proposition to bring together architecture and EE, thus potentially contributing to a field of knowledge that embraces design and education.     

Anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidea and var. angustifolia on 3T3-L1 adipocytes简

Objective

This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes.

Methods

Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content (TFC) and total phenolic content (TPC), respectively. The study was initiated by determining the maximum non-toxic dose (MNTD) of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD (1/2MNTD), after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density (OD) at 520 nm, respectively.

Results

The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents (QE)/100 g dry weight (DW), while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents (GAE)/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were (300.0±28.3) and (225.0±21.2) μg/ml, respectively, for var. deltoidea, while much lower MNTDs [(60.0±2.0) μg/ml for methanol extracts and (8.0±1.0) μg/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or 1/2MNTD significantly inhibited the maturation of preadipocytes. Conclusions: The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects.