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41.
Gonzalo M. A. Bermudez Luisina V. Battistón María C. García Capocasa Ana L. De Longhi 《Research in Science Education》2017,47(1):203-235
This study investigates the influence of school sector (private versus state schools) and student gender on knowledge of native fauna. Our main objectives were (a) to describe the knowledge of high school students from the province of Cordoba, Argentina with respect to native animal species, (b) to determine if any exotic species (introduced or domestic) are considered native, and (c) to analyze the effects of school sector and gender on the students’ knowledge of the native fauna. In total, 321 students aged 15–18 from 14 urban schools (8 state and 6 private schools) were asked to write down ten animals native to Córdoba, Argentina, in a free-list questionnaire. Relative frequencies and Generalized Linear Mixed Models (GLMM) were used to analyze the categorized (animal names) and continuous answers (quantity of responses, number of native animals, etc.), with the 25 most frequently mentioned species showing a predominance of native ones, of which “Puma” (Puma concolor) and “Andean condor” (Vultur gryphus) were the most prominent. An overrepresentation of mammalian species compared to other classes of chordates was also found, with high school students mentioning native and domestic species higher on the free-list. Using GLMM, we found that school sector had a significant effect on the number of native animals mentioned at both national and local levels, and on domestic and mixed species. Finally, male students mentioned more species and more native animals than their female counterparts. These findings were interpreted and discussed in light of sociocultural and traditional ecological knowledge theories, from which several implications arose related to research and practice. 相似文献
42.
Gonzalo M. A. Bermudez Sandra Díaz Ana L. De Longhi 《International Journal of Science Education》2018,40(1):46-66
People’s diminished awareness of plants, affected by anthropogenic environmental deterioration, has challenged science education to overcome the obstacles impeding a better understanding of their meaning and value. The aim of this study was to investigate the influence of the socioeconomic status of high-school students, as indicated by their attendance at private or state schools, on their knowledge of native plants. In total, 321 students aged 15–18 were asked to write down 10 plants native to Córdoba, Argentina, in a freelist questionnaire. Students listed a mean of 6.8 species of a total of 165 different categories of plant names. The majority of the species named were exotic to Córdoba (63%) or Argentina (50.6%, of which 33.8% were adventitious), indicating an ‘adventitious-to-native’ effect by which all spontaneously reproducing plants were presumed to be native species. However, the 20 most frequently named plants were mainly native, with ‘Algarrobo’ (Prosopis spp.) and ‘Espinillo’ (Vachellia caven) being the most mentioned. Students’ socioeconomic status had a significant effect on the number of species named, with the students of state schools (where the less well-off sectors of the society attend) mentioning more species and, among these, more native ones than the students from private schools. Furthermore, we defined size, colour and scent as being conspicuous traits of plant flowers that are relevant for human perception, and found that the most frequently named adventitious species, unlike the native ones, were those exhibiting big brightly-coloured flowers which ranged from being inodorous to having medium intensity scents. 相似文献
43.
Nieves R. Brisaboa Antonio Fariña Gonzalo Navarro José R. Paramá 《Information Retrieval》2007,10(1):1-33
Variants of Huffman codes where words are taken as the source symbols are currently the most attractive choices to compress
natural language text databases. In particular, Tagged Huffman Code by Moura et al. offers fast direct searching on the compressed
text and random access capabilities, in exchange for producing around 11% larger compressed files. This work describes End-Tagged
Dense Code and (s, c)-Dense Code, two new semistatic statistical methods for compressing natural language texts. These techniques permit simpler
and faster encoding and obtain better compression ratios than Tagged Huffman Code, while maintaining its fast direct search
and random access capabilities. We show that Dense Codes improve Tagged Huffman Code compression ratio by about 10%, reaching
only 0.6% overhead over the optimal Huffman compression ratio. Being simpler, Dense Codes are generated 45% to 60% faster
than Huffman codes. This makes Dense Codes a very attractive alternative to Huffman code variants for various reasons: they
are simpler to program, faster to build, of almost optimal size, and as fast and easy to search as the best Huffman variants,
which are not so close to the optimal size.
相似文献
| José R. ParamáEmail: |
44.
We describe a compression model for semistructured documents, called Structural Contexts Model (SCM), which takes advantage of the context information usually implicit in the structure of the text. The idea is to use a separate model to compress the text that lies inside each different structure type (e.g., different XML tag). The intuition behind SCM is that the distribution of all the texts that belong to a given structure type should be similar, and different from that of other structure types. 相似文献
45.
Antonio González Miguel Aranda Gonzalo López-Nicolás Carlos Sagüés 《Journal of The Franklin Institute》2019,356(2):1131-1153
This paper investigates the robust stability of a multiagent system moving to a desired rigid formation in presence of unknown time-varying communication delays and actuator faults. Each agent uses relative position measurements to implement the proposed control method, which does not require common coordinate references. However, the presence of time delays in the measurements, which is inherent to the communication links between agents, has a negative impact in the control system performance leading, in some cases, to instability. Furthermore, the robust stability analysis becomes more complex if failures on actuators are taken into account. In addition, delays may be subject to time variations, depending on network load, availability of communication resources, dynamic routing protocols, or other environmental conditions. To cope with these problems, a sufficient condition based on Linear Matrix Inequalities (LMI) is provided to ensure the robust asymptotic convergence of the agents to the desired formation. This condition is valid for any arbitrarily fast time-varying delays and actuator faults, given a worst-case point-to-point delay. Finally, simulation results show the performance of the proposed approach. 相似文献
46.
ABSTRACT The Instituto Tecnológico de Sonora (ITSON), a public and autonomous university in Cuidad Obregon, Sonora in Mexico has, since its inception, maintained a commitment to society and public service. To transform this commitment into valued results, it has used Mega Planning as its framework over the last eleven years. This article illustrates the impact an educational institution can have through a strategic planning and implementation approach that is focused on measurable objectives, the appropriate processes and activities, and the required resources for the development of its region (i.e., students and their environment). The article will begin with a brief background of the institution, its strategic approach, the subsequent curriculum and organization reform, and finally four key strategic programs that have had a positive social impact in the region: The Integrated Community Development Program; ITSON‐Consulting; Masters in Agribusiness; and the Software Factory. 相似文献
47.
Jos Antonio Salvador-Olivn Gonzalo Marco-Cuenca Rosario Arquero-Avils 《Journal of the Medical Library Association》2021,109(4):561
Objective:Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter.Methods:Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy.Results:The search strategy used in our filter added specific terms not included in PubMed''s systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%.Conclusions:The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision. 相似文献
48.
We present a new variable-length encoding scheme for sequences of integers, Directly Addressable Codes (DACs), which enables direct access to any element of the encoded sequence without the need of any sampling method. Our proposal is a kind of implicit data structure that introduces synchronism in the encoded sequence without using asymptotically any extra space. We show some experiments demonstrating that the technique is not only simple, but also competitive in time and space with existing solutions in several applications, such as the representation of LCP arrays or high-order entropy-compressed sequences. 相似文献
49.
Luís Gonzalo De la Casa Auxiliadora Mena Juán Carlos Ruiz-Salas Esperanza Quintero Mauricio R. Papini 《Learning & behavior》2018,46(1):49-59
Three experiments explored the link between reward shifts and latent inhibition (LI). Using consummatory procedures, rewards were either downshifted from 32% to 4% sucrose (Experiments 1–2), or upshifted from 4% to 32% sucrose (Experiment 3). In both cases, appropriate unshifted controls were also included. LI was implemented in terms of fear conditioning involving a single tone-shock pairing after extensive tone-only preexposure. Nonpreexposed controls were also included. Experiment 1 demonstrated a typical LI effect (i.e., disruption of fear conditioning after preexposure to the tone) in animals previously exposed only to 4% sucrose. However, the LI effect was eliminated by preexposure to a 32%-to-4% sucrose devaluation. Experiment 2 replicated this effect when the LI protocol was administered immediately after the reward devaluation event. However, LI was restored when preexposure was administered after a 60-min retention interval. Finally, Experiment 3 showed that a reward upshift did not affect LI. These results point to a significant role of negative emotion related to reward devaluation in the enhancement of stimulus processing despite extensive nonreinforced preexposure experience. 相似文献
50.
Estefanía Estvez Lpez Juan Herrero Olaizola Beln Martínez Ferrer Gonzalo Musitu Ochoa 《Psychology in the schools》2006,43(3):387-400
The present study aimed to analyze differences between aggressive and nonaggressive rejected students in four sets of variables: personal, family, school, and social. Participants in the study were 843 Spanish adolescents ranging in age from 11 to 16 years old, of whom 47% were boys. Results indicated that these two subgroups of rejected students show a different profile. Aggressive rejected students informed of lower levels of family self‐esteem, less parental support, higher levels of aggression between their parents at home, and a more offensive parent–child communication in comparison with nonaggressive rejected adolescents. Moreover, aggressive rejected students showed lower levels of academic self‐esteem, a more negative attitude toward school and studies, poorer relationships with teachers, and more academic difficulties than did adolescents in the nonaggressive rejected subgroup. Finally, aggressive rejected students indicated the presence of more undesirable life events and changes in their lives and, in general, higher levels of perceived stress. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 387–400, 2006. 相似文献