排序方式： 共有45条查询结果，搜索用时 31 毫秒
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Eduardo V.L. Nunes Alessandro J. Peixoto Tiago Roux Oliveira Liu Hsu 《Journal of The Franklin Institute》2014
This paper presents a solution to the problem of global exact output tracking for uncertain MIMO (multiple-input–multiple-output) linear plants with non-uniform arbitrary relative degree using output feedback sliding mode control. The key idea to overcome the relative degree obstacle is to generalize our previous hybrid estimation scheme to a multivariable version by combining, through switching, a standard linear lead filter with a non-linear one based on robust exact differentiators, achieving uniform global exponential practical stability and exact tracking. 相似文献
2.
[目的/意义] 旨在借助VR媒介技术,克服或弱化普通读者在古籍阅读中存在的古籍获取不便和古汉语理解、专业知识、特定文化背景知识、阅读动力不足的问题,促进古籍阅读推广与文化传播。[方法/过程] 利用文献调研方法分析梳理认知科学和教育技术领域相关理论,提出VR古籍系统设计原则与模型,基于单个案例分析,设计、开发、测试系统原型,最后利用实验方法以问卷方式收集评估数据,验证设计原则、模型的有用性。[结果/结论] 研究成果包括VR古籍系统设计原则、VR古籍系统理论模型、首例VR古籍系统应用原型、VR古籍系统使用理论,可为后续从事VR古籍系统研究与设计的科研人员和设计人员借鉴使用。 相似文献
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Luiz Rodrigo Augustemak de Lima Isabela de Carlos Back Everson Araújo Nunes Diego Augusto Santos Silva Edio Luiz Petroski 《Journal of sports sciences》2019,37(1):50-58
This study aimed to investigate if moderate to vigorous physical activity (MVPA) and aerobic fitness are associated with cardiovascular risk factors in HIV+ children and adolescents. Sixty-five children and adolescents (8 to 15 years) provided minutes of MVPA measured by accelerometers and peak oxygen uptake (peak VO2) by breath-by-breath respiratory exchange. Cardiovascular risk factors were characterized by body fat, blood pressure, total cholesterol, HDL-c, LDL-c, triglycerides, glucose, insulin, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α) and carotid intima-media thickness. Results indicated that higher MVPA was associated with lower values of total (β = ?3.566) and trunk body fat (β = ?3.495), total cholesterol (β = ?0.112) and LDL-c (β = ?0.830). Likewise, higher peak VO2 was associated with lower total (β = ?0.629) and trunk body fat values (β = ?0.592) and levels of CRP (β = ?0.059). The physically active participants had lower total cholesterol (?24.4 mg.dL?1) and LDL-c (?20.1 mg.dL?1) compared to participants judged to be insufficiently active. Moreover, participants with satisfactory peak VO? showed lower total (?4.1%) and trunk (?4.3%) body fat, CRP (?2.3 mg.L?1), IL-6 (?2.4 pg.mL?1) and TNF-α (?1.0 pg.mL?1) compared to low peak VO2 peers. High levels of MVPA and aerobic fitness may prevent developing of cardiovascular risk factors in children and adolescents HIV+. 相似文献
4.
Previous research has suggested that children in the early grades of primary school do not have much awareness of morphemes.
In this study, a priming paradigm was used to try to detect early signs of morphological representation of stems through a
spelling task presented to Portuguese children (N = 805; age range 6–9 years). Primes shared the stem with the targets and contained well-articulated, stressed vowels; the
stems of the target words and pseudo-words contained non-stressed schwa vowels, which typically result in spelling difficulties.
If priming proved effective, the well-articulated vowels in the prime should result in an improvement in the spelling of the
schwa vowels. Primes were presented in two conditions: in only-oral or in oral-plus-written form. Effectiveness of priming
was assessed by comparison with a no-priming condition. For both words and pseudowords, there was a significant interaction
between priming effects and grade. No priming effects were detected in 6- and 7-year-old children; oral-plus-written priming
produced higher rates of correct vowel spelling for 8- and 9-year-olds; only-oral priming was effective in improving the vowel
spelling of 9-year-olds. Thus older children can use morphological information under priming conditions when the prime and
the target are not phonologically transparent but there is no evidence to suggest that younger children do so. 相似文献
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Paolo M. Cunha Crisieli M. Tomeleri Matheus A. do Nascimento João Pedro Nunes Melissa Antunes Hellen C. G. Nabuco 《Journal of sports sciences》2013,31(24):2843-2848
ABSTRACTThe main purpose of this study was to compare the effects of resistance training (RT) performed with different training volumes on phase angle (PhA), body water components, and muscle quality (MQ) in untrained older adult women. A second purpose was to assess the relationship between PhA and MQ. Sixty-two older adult women (68.6 ± 5.0 years, 65.2 ± 13.3 kg, 156.1 ± 6.2 cm) were randomly assigned into one of the three groups: two training groups performed either 1 set (G1S) or 3 sets (G3S), or a control group (CG). Body water components and PhA were estimated by bioelectrical impedance (BIA). MQ was determined by dividing skeletal muscle mass estimated by dual-energy absorptiometry (DXA) by total muscle strength from three exercises. After the intervention period, both training groups demonstrated improvements (P < 0.05) when compared with CON for intracellular water, total body water, PhA, and MQ. These results suggest that RT can improve PhA, body water components, and MQ after 12 weeks of RT in untrained older women, regardless of training volume. Furthermore, changes in MQ were positively correlated with changes in PhA (r = 0.60, P < 0.01). 相似文献
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我国图情档学科认为博物馆是文化信息数字资源整合的主体之一。博物馆中以其展品为代表的文化信息资源对满足公众多样化的文化需求、增强中华文化竞争力起着重要作用。本文借助Citespace分析软件,通过对作者、机构、关键词可视化图谱的绘制,识别出我国图情档学科下以博物馆为主题词的科研文献成果概况、科研机构分布及研究热点词与其研究发展趋势。经分析得知,该学科下以博物馆为主题的研究可以分为两个阶段:第一阶段(1996-2008年)主要是博物馆文献资源的开发与利用、博物馆与图书馆文献资源的开发与利用、博物馆古籍保护管理工作以及古籍文献等主题。第二阶段(2009-2019年)主要探讨三馆馆际合作的资源整合路径、数字资源整合理论模式与合作机制等的研究,并结合相关文献内容,深入探讨以博物馆为主题的研究重点,基于此,我国图情档学科应以博物馆中丰富多样的文化信息资源为视角,开展涵盖档案馆、图书馆、博物馆的全种类、全范围的全文化信息数字资源整合。最后,本文围绕数字资源整合这一具有影响力的研究热点,探讨如何从图情档学科的角度出发,有效地涵盖博物馆,构建以图书馆、档案馆、博物馆三馆为主体的数字资源整合模式与机制,建立为公众文化精神需求服务的信息共享平台。 相似文献
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Ricardo?CamposEmail authorView author&#;s OrcID profile Ga?l?Dias Alípio?Mário?Jorge Célia?Nunes 《Information Retrieval》2017,20(4):363-398
Despite a clear improvement of search and retrieval temporal applications, current search engines are still mostly unaware of the temporal dimension. Indeed, in most cases, systems are limited to offering the user the chance to restrict the search to a particular time period or to simply rely on an explicitly specified time span. If the user is not explicit in his/her search intents (e.g., “philip seymour hoffman”) search engines may likely fail to present an overall historic perspective of the topic. In most such cases, they are limited to retrieving the most recent results. One possible solution to this shortcoming is to understand the different time periods of the query. In this context, most state-of-the-art methodologies consider any occurrence of temporal expressions in web documents and other web data as equally relevant to an implicit time sensitive query. To approach this problem in a more adequate manner, we propose in this paper the detection of relevant temporal expressions to the query. Unlike previous metadata and query log-based approaches, we show how to achieve this goal based on information extracted from document content. However, instead of simply focusing on the detection of the most obvious date we are also interested in retrieving the set of dates that are relevant to the query. Towards this goal, we define a general similarity measure that makes use of co-occurrences of words and years based on corpus statistics and a classification methodology that is able to identify the set of top relevant dates for a given implicit time sensitive query, while filtering out the non-relevant ones. Through extensive experimental evaluation, we mean to demonstrate that our approach offers promising results in the field of temporal information retrieval (T-IR), as demonstrated by the experiments conducted over several baselines on web corpora collections. 相似文献
10.
João Elias Dias Nunes Heitor Santos Cunha Zulmária Rezende Freitas Ana Maria Caixeta Nogueira Ana Raimunda Dâmaso Foued Salmen Espindola 《Journal of sports sciences》2016,34(10):945-950
The objective of this study is to evaluate the effect of interdisciplinary therapy in the parameters of the oxidative stress and the anti-inflammatory responses of obese adolescents. We selected 57 participants, who were randomly divided into 2 groups: interdisciplinary therapy group and a control group. After 6 months of intervention, 17 participants of the interdisciplinary therapy group and 8 of the control group returned for re-evaluation. The interdisciplinary therapy group participated in a treatment with 4 weekly sessions of exercise, a weekly group therapy session and a weekly nutritional education session. Blood parameters of oxidative stress and anti-inflammatory response were evaluated. The results demonstrated that there were significant increases in the interdisciplinary therapy group for superoxide dismutase activity (6.56 ± 3.22 to 11.40 ± 7.49) and ferric-reducing antioxidant potential concentration (532.91 ± 106.48 to 573.25 ± 112.57), although adiponectin levels did not reduce (40.9 ± 29.34 to 49.05 ± 41.22). A significant decrease in nitrite levels was also found (14.23 ± 8.48 to 11.45 ± 6.05). In the control group, significant reduction was found in adiponectin (31.56 ± 18.88 to 18.01 ± 11.66). This study suggests that interdisciplinary therapy for 6 months was effective in improving the anti-inflammatory responses and the antioxidant defences in obese adolescents. 相似文献