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Uddin Md. Elmarhomy Elsayed Masao Kazuhiro Jun-ichi 《Information processing & management》2007,43(6):1793
Field Association (FA) terms are a limited set of discriminating terms that can specify document fields. Document fields can be decided efficiently if there are many relevant FA terms in that documents. An earlier approach built FA terms dictionary using a WWW search engine, but there were irrelevant selected FA terms in that dictionary because that approach extracted FA terms from the whole documents. This paper proposes a new approach for extracting FA terms using passage (portions of a document text) technique rather than extracting them from the whole documents. This approach extracts FA terms more accurately than the earlier approach. The proposed approach is evaluated for 38,372 articles from the large tagged corpus. According to experimental results, it turns out that by using the new approach about 24% more relevant FA terms are appending to the earlier FA term dictionary and around 32% irrelevant FA terms are deleted. Moreover, precision and recall are achieved 98% and 94% respectively using the new approach. 相似文献
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This paper treats the problem of transmitting a Gaussian discrete-time Markov process over a time-discrete additive white Gaussian channel with noiseless feedback which is subjected to statistically unknown jamming noise (satisfying a given power constraint). The channel is used more than once during the interval between the production of successive source letters, and the jamming noise is either allowed to be correlated with the encoder output, or forced to be totally independent of it. The complete solution obtained in the paper under a minimax criterion indicates that the optimum encoder-decoder structures are linear,and the least favorable jamming noise is a Gaussian process. 相似文献
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Colak T Akca T Turkmenoglu O Canbaz H Ustunsoy B Kanik A Aydin S 《Journal of Zhejiang University. Science. B》2008,9(4):319-323
Objective: This prospective randomized clinical trial was conducted to evaluate the necessity of drainage after total thyroidectomy or lobectomy for benign thyroidal disorders. Methods: A total of 116 patients who underwent total thyroidectomy or lobectomy for benign thyroidal disorders were randomly allocated to be drained or not. Operative and postoperative outcomes including operating time, postoperative pain assessed by visual analogue scale (VAS), total amount of intramuscular analgesic administration, hospital stay, complications, necessity for re-operation and satisfaction of patients were all assessed. Results: The mean operating time was similar between two groups (the drained and non-drained groups). The mean VAS score was found to be significantly low in the non-drained group patients in postoperative day (POD) 0 and POD 1. The mean amount of intramuscular analgesic requirement was significantly less in the non-drained group. One case of hematoma, two cases of seroma and three cases of transient hypoparathyroidism occurred in the non-drained group, whereas one case of hematoma, two cases of seroma, two cases of wound infections and two cases of transient hypoparathyroidism occurred in the drained group. No patient needed re-operation for any complication. The mean hospital stay was significantly shorter and the satisfaction of patients was superior in the non-drained group. Conclusion: These findings suggest that postoperative complications cannot be prevented by using drains after total thyroidectomy or lobectomy for benign thyroid disorders. Furthermore, the use of drains may increase postoperative pain and the analgesic requirement, and prolong the hospital stay. In the light of these findings, the routine use of drains might not be necessary after thyroid surgery for benign disorders. 相似文献
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Association between 11beta-hydroxysteroid dehydrogenase type 1 gene polymorphisms and metabolic syndrome in Bosnian population 总被引：1，自引：0，他引：1
Dujic T Bego T Mlinar B Semiz S Malenica M Prnjavorac B Ostanek B Marc J Causevic A 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(1):76-85
Introduction:
The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of the hormonally inactive cortisone to active cortisol, thus facilitating glucocorticoid receptor activation in target tissues. Increased expression of 11β-HSD1 in adipose tissue has been associated with obesity and insulin resistance. In this study, we investigated the association of two 11β-HSD1 gene (HSD11B1) polymorphisms with the metabolic syndrome (MetS) and its characteristics in the Bosnian population.Materials and methods:
The study included 86 participants: 43 patients diagnosed with MetS and 43 healthy controls. Subjects were genotyped for two HSD11B1 gene polymorphisms: rs846910: G>A and rs45487298: insA, by the high resolution melting curve analysis. Genotype distribution and an influence of genotypes on clinical and biochemical parameters were assessed.Results:
There was no significant difference in the mutated allele frequencies for the two HSD11B1 gene polymorphisms between MetS patients and controls. In MetS patients, no significant associations between disease-associated traits and rs45487298: insA were found. Regarding rs846910: G>A variant, heterozygous patients (G/A) had significantly lower systolic (P = 0.017) and diastolic blood pressure (P = 0.015), lower HOMA-IR index (P = 0.011) and higher LDL-cholesterol levels (P = 0.049), compared to the wild-type homozygotes. In the control group, rs45487298: insA polymorphism was associated with lower fasting plasma insulin levels (P = 0.041), lower homeostasis model assessment insulin resistance (HOMA-IR) index (P = 0.041) and lower diastolic blood pressure (P = 0.048). Significant differences between rs846910: G>A genotypes in controls were not detected. Haplotype analysis confirmed the association of rs45487298: insA with markers of insulin resistance in the control subjects.Conclusions:
Our results indicate that a common rs45487298: insA polymorphism in HSD11B1 gene may have a protective effect against insulin resistance. 相似文献6.
Fredrik Jeppsson Jesper Haglund Tamer G. Amin 《International Journal of Science Education》2015,37(5-6):780-805
Many studies have previously focused on how people with different levels of expertise solve physics problems. In early work, focus was on characterising differences between experts and novices and a key finding was the central role that propositionally expressed principles and laws play in expert, but not novice, problem-solving. A more recent line of research has focused on characterising continuity between experts and novices at the level of non-propositional knowledge structures and processes such as image-schemas, imagistic simulation and analogical reasoning. This study contributes to an emerging literature addressing the coordination of both propositional and non-propositional knowledge structures and processes in the development of expertise. Specifically, in this paper, we compare problem-solving across two levels of expertise—undergraduate students of chemistry and Ph.D. students in physical chemistry—identifying differences in how conceptual metaphors (CMs) are used (or not) to coordinate propositional and non-propositional knowledge structures in the context of solving problems on entropy. It is hypothesised that the acquisition of expertise involves learning to coordinate the use of CMs to interpret propositional (linguistic and mathematical) knowledge and apply it to specific problem situations. Moreover, we suggest that with increasing expertise, the use of CMs involves a greater degree of subjective engagement with physical entities and processes. Implications for research on learning and instructional practice are discussed. 相似文献
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A growing body of research has examined the experiential grounding of scientific thought and the role of experiential intuitive knowledge in science learning. Meanwhile, research in cognitive linguistics has identified many conceptual metaphors (CMs), metaphorical mappings between abstract concepts and experiential source domains, implicit in everyday and scientific language. However, the contributions of CMs to scientific understanding and reasoning are still not clear. This study explores the roles that CMs play in scientific problem-solving through a detailed analysis of two physical chemistry PhD students solving problems on entropy. We report evidence in support of three claims: a range of CMs are used in problem-solving enabling flexible, experiential construals of abstract scientific concepts; CMs are coordinated with one another and other resources supporting the alignment of qualitative and quantitative reasoning; use of CMs grounds abstract reasoning in a “narrative” discourse incorporating conceptions of paths, agents, and movement. We conclude that CMs should be added to the set of intuitive resources others have suggested contribute to expertise in science. This proposal is consistent with two assumptions: that cognition is embodied and that internal cognitive structures and processes interact with semiotic systems. The implications of the findings for learning and instruction are discussed. 相似文献
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Urban High School Students’ IT/STEM Learning: Findings from a Collaborative Inquiry- and Design-Based Afterschool Program 总被引：1，自引：0，他引：1
Mesut Duran Margret Höft Dan B. Lawson Brahim Medjahed Elsayed A. Orady 《Journal of Science Education and Technology》2014,23(1):116-137
This exploratory study examines the impact of a collaborative inquiry- and design-based afterschool program on urban high school students’ IT/STEM learning—using information technology (IT) within the context of science, technology, engineering, and mathematics (STEM). The study used a mixed methods design, involving 77 participants within two cohort groups, each participating in an eighteen-month intervention period. Data were collected from the pre- and post-surveys, analysis of the participants’ IT/STEM projects, external evaluation reports, and follow-up interviews. Findings indicate that the program had a significant impact on students’ technology and IT/STEM skills, frequency of technology use, and understanding of IT use in STEM-oriented fields. Some degree of impact on attitude changes toward IT/STEM and career aspirations in these fields was also in evidence. The study demonstrates that IT/STEM experiences supported through technology-enhanced, inquiry- and design-based collaborative learning strategies have significant impact on urban high school students’ IT/STEM learning. Effect of afterschool programs on attitude changes and IT/STEM-related career aspirations of urban high school students are recommended areas of further investigation. 相似文献