LABRADOR: Efficiently publishing relational databases on the web by using keyword-based query interfaces     

Filipe Mesquita  Altigran S. da Silva  Edleno S. de Moura  Pável Calado  Alberto H.F. Laender 《Information processing & management》2007

A vast amount of valuable information, produced and consumed by people and institutions, is currently stored in relational databases. For many purposes, there is an ever increasing demand for having these databases published on the Web, so that users can query the data available in them. An important requirement for this to happen is that query interfaces must be as simple and intuitive as possible. In this paper we present LABRADOR, a system for efficiently publishing relational databases on the Web by using a simple text box query interface. The system operates by taking an unstructured keyword-based query posed by a user and automatically deriving an equivalent SQL query that fits the user’s information needs, as expressed by the original query. The SQL query is then sent to a DBMS and its results are processed by LABRADOR to create a relevance-based ranking of the answers. Experiments we present show that LABRADOR can automatically find the most suitable SQL query in more than 75% of the cases, and that the overhead introduced by the system in the overall query processing time is almost insignificant. Furthermore, the system operates in a non-intrusive way, since it requires no modifications to the target database schema.  相似文献   

From Hamburg to Belem: the limits of technocratic thinking in adult learning education     

Carlos Alberto Torres 《International Journal of Lifelong Education》2015,34(1):22-31

This article discusses some of the generalized analyses of adult learning education, mostly informed by technocratic thinking, highlighting perceived trends in adult learning education between CONFINTEA V and CONFITEA VI. Those trends could be understood as challenges. Employing a political sociology of adult learning education as a critique of instrumental reason is advanced.  相似文献   

State-space representation and realization of time-varying linear input—output functions     

Alberto Isidori  Antonio Ruberti 《Journal of The Franklin Institute》1976,301(6):573-592

In the present paper, two different general conditions for the existence of linear, finite-dimensional, reversible state-space representations are presented. These are compared with the well-known existence conditions arising in realization theory. The paper also gives a short discussion of time-invariant systems.  相似文献   

Strategies for counterresistance: Toward sociotransformative constructivism and learning to teach science for diversity and for understanding     

Alberto J. Rodriguez 《科学教学研究杂志》1998,35(6):589-622

This article reports on two types of resistance by preservice science teachers: resistance to ideological change and resistance to pedagogical change. The former has to do with the feelings of disbelief, defensiveness, guilt, and shame that Anglo-European preservice teachers experience when they are asked to confront racism and other oppressive social norms in class discussions. Resistance to pedagogical change has to do with the roles that preservice teachers feel they need to play to manage conflicting messages about what they are expected to do from their cooperating teachers (cover the curriculum and maintain class control) and from their university supervisors (implement student-centered, constructivist class activities), and about what they desire to do as emerging teachers. Although these two forms of resistance are closely linked, in the literature they are extensively reported separately. This study suggests a sociotransformative constructivist orientation as a vehicle to link multicultural education and social constructivist theoretical frameworks. By using this orientation, specific pedagogical strategies for counterresistance were found effective in helping preservice teachers learn to teach for diversity and understanding. These strategies for counterresistance were primarily drawn from the qualitative analysis of a yearlong project with secondary science preservice teachers. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 589–622, 1998.  相似文献   

Special Theory of Relativity,Conceptual Change and History of Science     

Villani  Alberto  Arruda  Sergio M. 《Science & Education》1998,7(1):85-100

The problem of the learning of Special Theory of Relativity by secondary and college students is analysed. It is stressed that the results of the studies which attempted to evaluate students' learning are ambiguous and intriguing. Also the history of the emergence and acceptance of the theory by the scientific community itself at the beginning of the 20th century is analysed. Three fundamental steps are described: a) the publication of Lorentz's Transformation Equations, their interpretation in the context of the Electron Theory and their consequent acceptance by the scientific community; b) the presentation by Einstein of two postulates, namely the Relativity Principle and Einstein's Principle of the Invariance of the Speed of Light, and their partial acceptance; c) the rejection of the Electron Theory and the final acceptance of the Theory of Relativity simultaneously with the development of the General Theory of Relativity. The analogy between historical and learning processes provides some suggestions to improve the teaching of the theory.  相似文献   

Estimating fat-free mass in elite youth male soccer players: cross-validation of different field methods and development of prediction equation     

Diego Munguía-Izquierdo  Luis Suárez-Arrones  Valter Di Salvo  Victor Paredes-Hernández  Ignacio Ara  Alberto Mendez-Villanueva 《Journal of sports sciences》2019,37(11):1197-1204

This study determined the most effective field method for quantifying fat-free mass (FFM) in elite youth male soccer players compared to dual X-ray absorptiometry (DXA) values and to develop prediction equations for FFM based on anthropometric variables. Forty-one male elite-standard youth soccer players, ages 16.2–18.0 years, undertook FFM assessments including bioelectrical impedance analysis, and different skinfold-based prediction equations. DXA provided a criterion measure of FFM. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses to develop soccer-specific prediction equations. Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998) equations showed the lowest biases, and no significant, standardized, and substantial differences against DXA. The new youth soccer-specific anthropometric equation explained 91% of the DXA-derived FFM variance using three circumferences, eight skinfolds, and one bone breadth. All field methods compared in this study may not be adequate for estimating FFM in elite youth male soccer players, except the equations of Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998). We recommend the use of the new soccer-specific equation proposed in this study as a valid alternative to DXA to quantify FFM among elite youth male players.  相似文献   

Independent and joint associations of physical activity and fitness with fibromyalgia symptoms and severity: The al-Ándalus project     

Víctor Segura-Jiménez  Alberto Soriano-Maldonado  Fernando Estévez-López  Inmaculada C. Álvarez-Gallardo  Manuel Delgado-Fernández  Jonatan R. Ruiz 《Journal of sports sciences》2017,35(15):1565-1574

We examined independent and joint associations of objectively measured physical activity (PA) and physical fitness (PF) with pain, fatigue and the overall impact of fibromyalgia in 386 fibromyalgia women aged 51.2 ± 7.6 years. Levels of PA (light, moderate and vigorous) and PF were measured with triaxial accelerometry and the Senior Fitness Test, respectively. We used the Short-Form health survey-36 pain sub-scale and the Multidimensional Fatigue Inventory to assess pain and multiple dimensions of fatigue, respectively. The impact of fibromyalgia was studied with the Revised Fibromyalgia Impact Questionnaire (FIQR). Both, total PA and global PF were independently associated with pain pressure threshold, SF-36 pain, reduced activity, reduced motivation and FIQR total score (all, P ≤ 0.027). The associations between total PA and symptoms were weaker than those observed between global PF and symptoms. Overall, unfit patients with low PA showed a worse profile that fit patients with high PA (all, P ≤ 0.001). In summary, PA and PF are independently associated with pain, fatigue and the overall impact of fibromyalgia in women. Although PF presented greater associations with symptoms, the results suggest that both being physically active and keep adequate fitness levels might be convenient for fibromyalgia women.  相似文献   

The location of the tibial accelerometer does influence impact acceleration parameters during running     

Angel Gabriel Lucas-Cuevas  Alberto Encarnación-Martínez  Andrés Camacho-García  Salvador Llana-Belloch  Pedro Pérez-Soriano 《Journal of sports sciences》2017,35(17):1734-1738

Tibial accelerations have been associated with a number of running injuries. However, studies attaching the tibial accelerometer on the proximal section are as numerous as those attaching the accelerometer on the distal section. This study aimed to investigate whether accelerometer location influences acceleration parameters commonly reported in running literature. To fulfil this purpose, 30 athletes ran at 2.22, 2.78 and 3.33 m · s^–1 with three accelerometers attached with double-sided tape and tightened to the participants’ tolerance on the forehead, the proximal section of the tibia and the distal section of the tibia. Time-domain (peak acceleration, shock attenuation) and frequency-domain parameters (peak frequency, peak power, signal magnitude and shock attenuation in both the low and high frequency ranges) were calculated for each of the tibial locations. The distal accelerometer registered greater tibial acceleration peak and shock attenuation compared to the proximal accelerometer. With respect to the frequency-domain analysis, the distal accelerometer provided greater values of all the low-frequency parameters, whereas no difference was observed for the high-frequency parameters. These findings suggest that the location of the tibial accelerometer does influence the acceleration signal parameters, and thus, researchers should carefully consider the location they choose to place the accelerometer so that equivalent comparisons across studies can be made.  相似文献   

Linking Bakhtin with feminist poststructuralism to unravel the allure of auto/biographies     

Alberto J. Rodriguez 《Research in Science Education》2000,30(1):13-21

By linking feminist poststructuralism with Bakhtin's concepts of voice and ventriloquation, an approach is proposed for the critical engagement with auto/biographical text. It is argued that by becoming better aware of the teller's intentionality and her/his insights gained from telling a (re)constructed version of self, the listener and the teller can engage in personal and socially transformative dialog. This dialog can assist the teller/listener to move from superficial affirmation of (re)interpreted lived experiences to more socially responsive action. An example is provided to illustrate implications of this approach for science teaching and education research.  相似文献   

A computer aided consultant system for mammogram diagnosis     

Alberto Rocha TONG Fu 《上海大学学报(英文版)》1999,3(4):293-298

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