Improving ranking performance with cost-sensitive ordinal classification via regression     

Yu-Xun Ruan  Hsuan-Tien Lin  Ming-Feng Tsai 《Information Retrieval》2014,17(1):1-20

This paper proposes a novel ranking approach, cost-sensitive ordinal classification via regression (COCR), which respects the discrete nature of ordinal ranks in real-world data sets. In particular, COCR applies a theoretically sound method for reducing an ordinal classification to binary and solves the binary classification sub-tasks with point-wise regression. Furthermore, COCR allows us to specify mis-ranking costs to further improve the ranking performance; this ability is exploited by deriving a corresponding cost for a popular ranking criterion, expected reciprocal rank (ERR). The resulting ERR-tuned COCR boosts the benefits of the efficiency of using point-wise regression and the accuracy of top-rank prediction from the ERR criterion. Evaluations on four large-scale benchmark data sets, i.e., "Yahoo! Learning to Rank Challenge" and "Microsoft Learning to Rank,” verify the significant superiority of COCR over commonly used regression approaches.  相似文献   

Assessing South China (Guangzhou) High School Students’ Views on Nature of Science: A Validation Study     

Feng Deng  Ching Sing Chai  Chin-Chung Tsai  Tzung-Jin Lin 《Science & Education》2014,23(4):843-863

Research on students’ views on nature of science (VNOS) in Asian countries such as China is notably lacking. This study aimed to develop and validate an instrument to measure South China high school students’ VNOS. Based on the previously acquired qualitative data, the instrument included seven VNOS dimensions which reflect the crucial aspects of NOS indicated by the literature and/or the dominating ideology in China (i.e., Marxism). A sample (N = 604) was randomly divided into two groups used for exploratory analyses and confirmatory analyses. The results indicated that the instrument expressed satisfactory reliability and validity and the seven NOS dimensions could be explained by a higher-order dimension. That is, the data of this study supported the multi-dimensional framework that treats VNOS as comprising several more-or-less correlated dimensions. Two distinct dimensions, namely “Accumulative-Empirical Source” and “Pragmatic Justification” which have not been explicitly specified in the past literature, were found. In addition, the Chinese high school students generally held a constructivist/relativist-oriented view of all seven dimensions. Differences in gender and grade level were hardly observed in any dimension of the instrument. The findings are further discussed through a socio-cultural lens to enrich the current understanding of VNOS.  相似文献   

Family man in advertising? A content analysis of male domesticity and fatherhood in Taiwanese commercials     

Wanhsiu Sunny Tsai 《亚洲交流杂志》2013,23(4):423-439

This study examines how Taiwanese commercials represent women and men, particularly men, in the family context as spouses and parents. A content analysis of prime-time commercials indicates that advertising representations of gender roles have made only slight and slow progress. Men are much less likely than women to be shown doing housework and taking care of children. When men are shown as nurturant fathers, their involvements with children are limited to playing with offspring.  相似文献   

The Commonalities and Dissonances Between High-School Students' and Their Science Teachers' Conceptions of Science Learning and Conceptions of Science Assessment: A Taiwanese sample study     

Tzung-Jin Lin  Chin-Chung Tsai 《International Journal of Science Education》2013,35(3):382-405

The main purpose of this study was to concurrently investigate Taiwanese high-school students' and their science teachers' conceptions of learning science (COLS) and conceptions of science assessment (COSA). A total of 1,048 Taiwanese high-school students and their 59 science teachers were invited to fill out two questionnaires assessing their COSA and COLS. The main results indicated that, first, although a handful of different patterns occurred, students and teachers were found to have similar COLS–COSA patterns. In general, students and teachers with COSA as reproducing knowledge and rehearsing tended to possess lower-level COLS, such as learning science as memorizing, testing, and calculating and practicing. In contrast, if students and teachers viewed science assessment as improving learning and problem-solving, they would be prone to regard science learning as increase of knowledge, applying, and understanding and seeing in a new way. However, the students' conceptions did not align with those of the teachers' in certain aspects. The students tended to regard science learning and assessment at a superficial level (COLS as ‘memorizing’, ‘testing’, and ‘calculating and practicing’ and COSA as ‘reproducing knowledge’), while the teachers’ conceptions were at a more sophisticated level (COLS as ‘application’ and ‘understanding and seeing in a new way’ and COSA as ‘improving learning’). It is evident that a dissonance exists between the students' and teachers' COLS and COSA. Based on the results, practical implications and suggestions for future research are discussed.  相似文献   

Impact of a Scientist–Teacher Collaborative Model on Students,Teachers, and Scientists     

Paichi Pat Shein  Chun-Yen Tsai 《International Journal of Science Education》2013,35(13):2147-2169

Collaborations between the K-12 teachers and higher education or professional scientists have become a widespread approach to science education reform. Educational funding and efforts have been invested to establish these cross-institutional collaborations in many countries. Since 2006, Taiwan initiated the High Scope Program, a high school science curriculum reform to promote scientific innovation and inquiry through an integration of advanced science and technology in high school science curricula through partnership between high school teachers and higher education scientists and science educators. This study, as part of this governmental effort, a scientist–teacher collaborative model (STCM) was constructed by 8 scientists and 4 teachers to drive an 18-week high school science curriculum reform on environmental education in a public high school. Partnerships between scientists and teachers offer opportunities to strengthen the elements of effective science teaching identified by Shulman and ultimately affect students’ learning. Mixed methods research was used for this study. Qualitative methods of interviews were used to understand the impact on the teachers’ and scientists’ science teaching. A quasi-experimental design was used to understand the impact on students’ scientific competency and scientific interest. The findings in this study suggest that the use of the STCM had a medium effect on students’ scientific competency and a large effect on students’ scientific individual and situational interests. In the interviews, the teachers indicated how the STCM allowed them to improve their content knowledge and pedagogical content knowledge (PCK), and the scientists indicated an increased knowledge of learners, knowledge of curriculum, and PCK.  相似文献   

High school students’ approaches to learning physics with relationship to epistemic views on physics and conceptions of learning physics     

Guo-Li Chiou  Chin-Chung Tsai 《Research in Science & Technological Education》2013,31(1):1-15

Background and purpose : Knowing how students learn physics is a central goal of physics education. The major purpose of this study is to examine the strength of the predictive power of students’ epistemic views and conceptions of learning in terms of their approaches to learning in physics. Sample, design and method : A total of 279 Taiwanese high school students ranging from 15 to 18?years old participated in this study. Three questionnaires for assessing high school students’ epistemic views on physics, conceptions of learning physics and approaches to learning physics were developed. Step-wise regression was performed to examine the predictive power of epistemic views on physics and conceptions of learning physics in terms of their approaches to learning physics. Results and conclusion: The results indicated that, in general, compared to epistemic views on physics, conceptions of learning physics are more powerful in predicting students’ approaches to learning physics in light of the regression models. That is, students’ beliefs about learning, compared with their beliefs about knowledge, may be more associated with their learning approaches. Moreover, this study revealed that the higher-level conceptions of learning physics such as ‘Seeing in a new way’ were more likely to be positively correlated with the deep approaches to learning physics, whereas the lower-level conceptions such as ‘Testing’ were more likely to positively explain the surface approaches, as well as to negatively predict the deep approaches to learning physics.  相似文献   

High school students’ scientific epistemological beliefs,motivation in learning science,and their relationships: A comparative study within the Chinese culture   总被引：1，自引：0，他引：1  

Tzung-Jin Lin  Feng Deng  Ching Sing Chai  Chin-Chung Tsai 《International Journal of Educational Development》2013

This study explored the differences in high school students’ scientific epistemological beliefs (SEBs), motivation in learning science (MLS), and the different relationships between them in Taiwan and China. 310 Taiwanese and 302 Chinese high school students’ SEBs and MLS were assessed quantitatively. Taiwanese students generally were more prone to believe that scientific reality is invented, the development of scientific knowledge is culture-dependent, and scientific knowledge is always changing and its status is tentative than the Chinese students were. Yet, the Taiwanese students perceived higher test anxiety in science than the Chinese students did. Moreover, Chinese students who have a stronger belief that science knowledge is changing and tentative are more likely to perceive themselves as having higher test anxiety in science. The results suggest that the role of culture might have an impact on students’ SEBs and their MLS.  相似文献   

Rapid detection of natriuretic peptides by a microfluidic LabChip analyzer with DNA aptamers: Application of natriuretic peptide detection     

Ming-Cheng Lin  Jiraporn Nawarak  Tai-Yuan Chen  Hsien-Yu Tsai  Jung-Feng Hsieh  Supachok Sinchaikul    Shui-Tein Chen 《Biomicrofluidics》2009,3(3)

Rapid detection of brain natriuretic peptide (BNP) concentration can be used for the diagnosis of acute heart failure and for the evaluation of the effectiveness of a clinical therapy. We used the systematic evolution of ligands by exponential enrichment method to develop DNA aptamers for BNP whose sequences were determined by cloning method and consensus sequence analysis. A total of eight conserved sequences was identified. By combining the fluorescent-labeled aptamers with fast protein lab-on-chip analysis, we could achieve quantification of BNP concentrations with high speed, sensitivity, and specificity.  相似文献   

EP-based adaptive tracker with observer and fault estimator for nonlinear time-varying sampled-data systems against actuator failures     

Jason S.-H. Tsai  Chao-Lung Wei  Shu-Mei Guo  Leang S. Shieh  Ce R. Liu 《Journal of The Franklin Institute》2008,345(5):508-535

An evolutionary programming-based adaptive observer is presented in this paper to improve the performance of state estimation of nonlinear time-varying sampled-data systems. Also, this paper presents a novel state-space adaptive tracker together with the proposed observer and estimation schemes for nonlinear time-varying sampled-data systems having actuator failures. For the class of slowly varying nonlinear time-varying systems, the proposed methodology is able to achieve the desired fault detection and performance recovery for the originally well-designed systems, as long as the controller having the high-gain property. For practical implementation, we utilize the advantages of digital redesign methodology to convert a well-designed high-gain analog controller/observer into its corresponding low-gain digital controller/observer. Illustrative examples are given to demonstrate the effectiveness of the proposed method. The developed digitally redesigned adaptive tracker with the proposed observer and estimator is suitable for implementation by using microprocessors.  相似文献   

Effects of periodic carbohydrate ingestion on endurance and cognitive performances during a 40-km cycling time-trial under normobaric hypoxia in well-trained triathletes     

Yi-Hung Liao  Toby Mündel  Yan-Ting Yang  Chen-Chan Wei  Shiow-Chwen Tsai 《Journal of sports sciences》2019,37(16):1805-1815

The purpose of this study was to examine CHO ingestion on a cognitive task using a field-simulated time-trial (TT) under hypoxia in well-trained triathletes. Ten male triathletes (age: 22.1 ± 1.1 years; VO₂max: 59.4 ± 1.4 ml/kg/min) participated in this double-blind/crossover/counter-balanced design study. Participants completed 3 TT trials: 1) normoxic placebo (NPLA; FiO₂ = 20.9%), 2) hypoxic placebo (HPLA; FiO₂ = 16.3%), and 3) hypoxic CHO (HCHO; 6% CHO provided as 2 ml/kg/15 min; FiO₂ = 16.3%). During the TT, physiological responses (SpO₂, HR, RPE, and blood glucose/lactate), cognitive performance, and cerebral haemodynamics were measured. Hypoxia reduced TT performance by ~3.5–4% (p < 0.05), but CHO did not affect TT performance under hypoxia. For the cognitive task, CHO slightly preserved exercise-induced cognitive reaction speed but did not affect response accuracy during hypoxic exercise. However, CHO did not preserve the decreased Hb-Diff (cerebral blood flow, CBF) and increased HHb in the prefrontal lobe (p < 0.05) during hypoxic exercise, and CHO failed to preserve hypoxia-suppressed prefrontal CBF and tissue oxygen saturation. In conclusion, the present study demonstrates that CHO is effective in sustaining reaction speed for a cognitive task but not promoting TT performance during hypoxic exercise, which would be important for strategy-/decision-making when athletes compete at moderate high-altitude.  相似文献