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51.
TIJAH: Embracing IR Methods in XML Databases 总被引:1,自引:0,他引:1
Johan?ListEmail author Vojkan?Mihajlovi? Georgina?Ramírez Arjen?P.?de?Vries Djoerd?Hiemstra Henk?Ernst?Blok 《Information Retrieval》2005,8(4):547-570
This paper discusses our participation in INEX (the Initiative for the Evaluation of XML Retrieval) using the TIJAH XML-IR system. TIJAHs system design follows a standard layered database architecture, carefully separating the conceptual, logical and physical levels. At the conceptual level, we classify the INEX XPath-based query expressions into three different query patterns. For each pattern, we present its mapping into a query execution strategy. The logical layer exploits score region algebra (SRA) as the basis for query processing. We discuss the region operators used to select and manipulate XML document components. The logical algebra expressions are mapped into efficient relational algebra expressions over a physical representation of the XML document collection using the pre-post numbering scheme. The paper concludes with an analysis of experiments performed with the INEX test collection. 相似文献
52.
Tertiary Education and Management - This empirical study explores higher education advertising campaigns displayed in five world cities: Boston, New York, Oslo, Tokyo, and Toronto. The study... 相似文献
53.
Leticia I. RAMíREZ-CAVAZOS Charles JUNGHANNS Rakesh NAIR Diana L. CáRDENAS-CHáVEZ Carlos HERNáNDEZ-LUNA Spiros N. AGATHOS Roberto PARRA 《Journal of Zhejiang University. Science. B》2014,15(4):343-352
研究目的:优化获得血红密孔菌(P.sanguineus)的最佳培养基组成,提高耐热漆酶的产量。创新要点:获得了目前文献报道的最高水平的漆酶活力。研究方法:通过单因素试验研究了不同培养基(番茄汁、麦麸、麦芽提取物和葡萄糖细菌蛋白胨培养基)和不同组合诱导剂(大豆油、阿魏酸、没食子酸、二甲基苯胺、酸性蓝62和活性蓝19分别与硫酸铜组合诱导剂)对P.sanguineus产耐热漆酶的影响。在此基础上采用中心组合试验设计,进一步研究了番茄汁培养基结合硫酸铜和大豆油组合诱导剂对P.sanguineus产耐热漆酶的影响。利用SAS10.0和响应面分析方法对试验结果进行了统计分析和建立回归模型。重要结论:通过中心组合设计优化得出P.sanguineus产耐热漆酶的最优培养基条件:以36.8%番茄汁为培养基,以3 mmol/L硫酸铜和1%大豆油作为组合诱导剂。该条件下在10 L搅拌槽生物反应器中漆酶活力达到了143 000 IU/L(2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)为底物,pH值为3.0)。 相似文献
54.
Anshita Aggarwal Sant Ram Abhilasha Garg Rimesh Pal Anil Bhansali Priyanka Singh Sadhna Sharma J. S. Thakur Naresh Sachdeva Sanjay Kumar Bhadada 《Indian journal of clinical biochemistry : IJCB》2021,36(1):67
We aimed to estimate metabolic bone profile in a large cohort of healthy, adult Indian population to generate reference standards of serum calcium, phosphate and alkaline phosphatase (ALP), 25 (OH) Vitamin D and iPTH, and also to find out the prevalence of Vitamin D deficiency in healthy population. Apparently healthy people in the age group of 20–80 years, residing in the union territory of Chandigarh were chosen. Fasting samples for serum calcium, phosphate, albumin, alkaline phosphatase (ALP), 25 (OH) D and iPTH were collected and were processed on the same day. We recruited 930 healthy subjects from different subsectors of Chandigarh. Final analysis was done for 915 subjects. Out of this, 530 (58%) were women and 385 (42%) were men. The study participants were divided into two groups, less than and more than 50 years for the men and pre and post-menopausal for the women. The serum calcium, phosphate, ALP and iPTH were significantly higher in the post-menopausal women compared to the pre-menopausal women. The median plasma 25 (OH) D in men and women was 12.5 ng/mL and 14.3 ng/mL, respectively. 25 (OH) D deficiency was seen in 65.4% of individuals. 25 (OH) D levels co-related negatively with iPTH levels (r = − 0.4, p < 0.0001), and showed an increasing trend with age. We have thus presented metabolic bone profile of healthy, adult north Indian population. These reference values can be used for diagnosis and monitoring of various MBDs. Vitamin D deficiency is still rampant in our population in spite of increasing awareness. 相似文献
55.
Ram B. Sankar Pawan Kishore Tiwari Bijnan Bandyopadhyay Hemendra Arya 《Journal of The Franklin Institute》2021,358(12):6121-6135
The Mach number, angle of attack and altitude of operation for an interceptor vary widely during the course of its trajectory. As a result, the interceptor Center of Pressure (CP) locations move significantly around a given Center of Gravity (CG) location at these operating conditions. This results in an inevitable variation in aerodynamic static stability leading to stable and unstable operating regions. In order to ensure good speed of response during the interceptor homing phase, lesser static stability is desirable. Hence the requirement to handle aerodynamic instability at some other operating conditions in the interceptor envelope become inevitable. Since flexibility has a strong bearing on autopilot design, it becomes necessary to control unstable operating points in the presence of flexibility modes. Despite the static stability variation, aerodynamic design can control the level of maximum instability of the configuration. Hence the maximum static instability the autopilot can handle has to be specified for aerodynamic configuration design. This paper brings out the limitations of autopilot design in controlling an unstable interceptor with low bending mode frequencies in terms of maximum instability the autopilot design can handle, which serves as an important input for aerodynamic design. 相似文献
56.
Oskar Casquero Ramón Ovelar Jesús Romo Manuel Benito Mikel Alberdi 《Interactive Learning Environments》2016,24(1):49-67
The main objective of this paper is to analyse the effect of the affordances of a virtual learning environment and a personal learning environment (PLE) in the configuration of the students' personal networks in a higher education context. The results are discussed in light of the adaptation of the students to the learning network made up by two undergraduate, inter-university and online courses. Besides, we also examine the influence of this effect in the learning process. The findings reflect the effectiveness of a PLE for facilitating student participation and for assisting students in the creation of larger and more balanced personal networks with richer social capital. However, the findings do not provide evidences about a difference in the learning performance between the two environments. From a methodological point of view, this paper serves as an illustration of the analysis of personal networks on digital data collected from technology-enhanced learning environments. 相似文献
57.
Oliver and Soundararajan have recently discovered an unexpected bias in the distribution of prime numbers. Interestingly, the authors embarked on this research after hearing about a counter-intuitive result obtained upon comparison of two elementary coin tossing experiments. This article describes these experiments and presents both numerical and analytical methods for exploring the source of inspiration for their research. Elaboration of such key motivations or themes provides a way of bringing the excitement of recent mathematical discoveries to the undergraduate classroom. 相似文献
58.
Trajectories of Infants’ Biobehavioral Development: Timing and Rate of A‐Not‐B Performance Gains and EEG Maturation
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Leigha A. MacNeill Nilam Ram Martha Ann Bell Nathan A. Fox Koraly Pérez‐Edgar 《Child development》2018,89(3):711-724
This study examined how timing (i.e., relative maturity) and rate (i.e., how quickly infants attain proficiency) of A‐not‐B performance were related to changes in brain activity from age 6 to 12 months. A‐not‐B performance and resting EEG (electroencephalography) were measured monthly from age 6 to 12 months in 28 infants and were modeled using logistic and linear growth curve models. Infants with faster performance rates reached performance milestones earlier. Infants with faster rates of increase in A‐not‐B performance had lower occipital power at 6 months and greater linear increases in occipital power. The results underscore the importance of considering nonlinear change processes for studying infants’ cognitive development as well as how these changes are related to trajectories of EEG power. 相似文献
59.
Amit Ram Morarka 《Resonance》2016,21(5):457-465
Using an electrical component like a relay, the phenomenon of self inductance caneasily be demonstrated to undergraduate students. By wiring simple electrical components like relay, neon bulb and a DC power supply, intermittent back electromotive force (emf) can be generated in the range from 60 to 100 volt. The glowing of neon bulb provides visual evidence for the generation of large back emf due to self inductance. 相似文献
60.
ABSTRACTOnline writing courses have developed in importance to meet student learning and institutional expectations; over time, a controversy about training online instructors and building sustainable programs has emerged. This article relates training demands within the University of Arizona’s Writing Program and development of an online professional & technical writing certificate. The article proposes training instructors with master courses and building a sustained program through a participatory design to create a professional and integrated environment. 相似文献