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11.
S.V.Nageswara Rao S.Sitharama Iyengar C.E.Veni Madhavan 《Information processing & management》1985,21(5):433-442
A variety of data structures such as inverted file, multi-lists, quad tree, k-d tree, range tree, polygon tree, quintary tree, multidimensional tries, segment tree, doubly chained tree, the grid file, d-fold tree. super B-tree, Multiple Attribute Tree (MAT), etc. have been studied for multidimensional searching and related problems. Physical data base organization, which is an important application of multidimensional searching, is traditionally and mostly handled by employing inverted file. This study proposes MAT data structure for bibliographic file systems, by illustrating the superiority of MAT data structure over inverted file. Both the methods are compared in terms of preprocessing, storage and query costs. Worst-case complexity analysis of both the methods, for a partial match query, is carried out in two cases: (a) when directory resides in main memory, (b) when directory resides in secondary memory. In both cases, MAT data structure is shown to be more efficient than the inverted file method. Arguments are given to illustrate the superiority of MAT data structure in an average case also. An efficient adaptation of MAT data structure, that exploits the special features of MAT structure and bibliographic files, is proposed for bibliographic file systems. In this adaptation, suitable techniques for fixing and ranking of the attributes for MAT data structure are proposed. Conclusions and proposals for future research are presented. 相似文献
12.
Framing has become one of the most popular areas of research for scholars in communication and a wide variety of other disciplines, such as psychology, behavioral economics, political science, and sociology. Particularly in the communication discipline, however, ambiguities surrounding how we conceptualize and therefore operationalize framing have begun to overlap with other media effects models to a point that is dysfunctional. This article provides an in-depth examination of framing and positions the theory in the context of recent evolutions in media effects research. We begin by arguing for changes in how communication scholars approach framing as a theoretical construct. We urge scholars to abandon the general term “framing” altogether and instead distinguish between different types of framing. We also propose that, as a field, we refocus attention on the concept's original theoretical foundations and, more important, the potential empirical contributions that the concept can make to our field and our understanding of media effects. Finally, we discuss framing as a bridge between paradigms as we shift from an era of mass communication to one of echo chambers, tailored information and microtargeting in the new media environment. 相似文献
13.
The expression of chromosomal genes is regulated by posttranslational modification of both histone and nonhistone chromatin
proteins and ATP-dependent remodeling of chromatin. Dysfunction of the modification and remodeling machineries can lead to
several diseases, which include cancer, cardiac hypertrophy, and asthma. Many genetic diseases can also lead to malfunction
of the machinery. The enzymes responsible for chromatin organization are the new targets for therapeutics. Inhibitors and
activators of histone acetyltransferases and inhibitors of histone deacetylases may serve as new generation drugs. 相似文献
14.
OBJECTIVE: For nearly 25 years researchers have suggested that better taxonomic systems conceptualizing and reliably differentiating among different dimensions of maltreatment are required. This study examines the utility of three different characterizations of one dimension of maltreatment, chronicity, to predict child behavioral and emotional functioning in a sample of maltreated children. A secondary objective of the study is to examine additional parameters of maltreatment inherent in our definitions of chronicity: age at first report to CPS, extent and continuity of maltreatment. METHOD: The study consists of children reported for maltreatment (N=519) from the larger LONGSCAN study cohort. Lifetime maltreatment data were collected from CPS records and coded into two chronicity constructs: "developmental" and "calendar" definitions. Variables for age at first report, frequency, extent and continuity of maltreatment reports also were constructed. Hierarchical regression analyses were utilized to determine the extent to which the various chronicity constructs contributed to the prediction of child outcomes. RESULTS: The most salient definition of chronicity, in terms of its effects on child behavioral and emotional functioning, varied by outcome. The developmental definition was found to have the most balanced sensitivity across outcomes. Among other significant findings, extent and continuity of maltreatment contributed respectively to the prediction of behavior and emotional trauma symptoms. Early age at first report was a predictor of poor daily living skills. CONCLUSION: Chronicity is a complex construct. Findings indicate there are multiple parameters that make up the chronicity construct itself that may be important for understanding child outcomes. 相似文献
15.
Kalpana Mukunda Iyengar Howard L. Smith 《Educational Studies A Journal of the American Educational Studies Association》2016,52(2):95-118
Many children from diverse cultures experience disconnectedness between their home and school. As they attempt to reconcile the conflicts among their multiple worlds, they must negotiate their situatedness in a variety of contexts, i.e., home community versus school, and construct a multifaceted identity. Absent support from school, Asian Indian American adolescents engage in acts of cultural preservation (CP), which, in turn, support their scholastic achievement. This article explores the thematic content of a group of Asian Indian American children's creative writing generated for the Kahani Project—a culturally contextualized version of Writers’ Workshop. In their texts, the six adolescents discuss the importance of their cultural traditions as tools to contest the various micro-aggressions they experience in school. Data from this study argue for cultural inclusion, not only for those at risk, but also for those students who successfully navigate a mainstream curriculum. 相似文献
16.
PROSPECTS - Covid-19 has put education in a challenging place. With millions of children out of school, education needs to reinvent itself. During the pandemic, communities have used this... 相似文献
17.
Leo Ng Simon M. Rosalie Dorianne Sherry Wei Bing Loh Andreas M. Sjurseth Shrikant Iyengar 《Journal of sports sciences》2018,36(19):2210-2216
Research has revealed that field hockey drag flickers have greater odds of hip and lumbar injuries compared to non-drag flickers (DF). This study aimed to compare the biomechanics of a field hockey hit and a specialised field hockey drag flick. Eighteen male and seven female specialised hockey DF performed a hit and a drag flick in a motion analysis laboratory with an 18-camera three-dimensional motion analysis system and a calibrated multichannel force platform to examine differences in lower limb and lumbar kinematics and kinetics. Results revealed that drag flicks were performed with more of a forward lunge on the left lower limb resulting in significantly greater left ankle dorsiflexion, knee, hip and lumbar flexion (Ps<0.001) compared to a hit. Drag flicks were also performed with significantly greater lateral flexion (P < 0.002) and rotation of the lumbar spine (P < 0.006) compared to a hit. Differences in kinematics lead to greater shear, compression and tensile forces in multiple left lower limb and lumbar joints in the drag flick compared to the hit (P < 0.05). The biomechanical differences in drag flicks compared to a hit may have ramifications with respect to injury in field hockey drag flickers. 相似文献
18.
PROSPECTS - COVID-19 has disrupted education for millions of children across the globe. The education community is re-imagining and re-designing to build back better. This Viewpoint takes the... 相似文献
19.
Clyde W. Holsapple Deepak Iyengar Haihao Jin Shashank Rao 《The Information Society》2013,29(4):199-218
Advances in Internet and other digital technologies have opened up new channels and methods for online business. They have also led to a situation where the same channels can be abused and misused. One of these forms of technology abuse, which is becoming increasingly prevalent these days, is the piracy of digital content. This article introduces a relatively comprehensive and unified theoretical framework for studying and understanding a major aspect of digital piracy: namely, software piracy. Based on Routine Activities Theory, Rational Choice Theory, and guardianship concepts, the framework identifies key parameters that can affect the incidence of software piracy. We apply the framework in conducting a systematic examination of 75 articles dealing with software piracy. The examination reveals that a considerable number of parameters have received little or no attention from software-piracy researchers. In addition to suggesting research opportunities, the framework furnishes a systematic approach for structuring the design of future research studies in the realm of software piracy. The insights furnished by this article contribute to future investigations of the software-piracy phenomenon that are needed to avert the economic and social damage caused by software piracy. 相似文献
20.
Zakiya S. Wilson Sitharama S. Iyengar Su-Seng Pang Isiah M. Warner Candace A. Luces 《Journal of Science Education and Technology》2012,21(5):581-587
Increasing college degree attainment for students from disadvantaged backgrounds is a prominent component of numerous state and federal legislation focused on higher education. In 1999, the National Science Foundation (NSF) instituted the ??Computer Science, Engineering, and Mathematics Scholarships?? (CSEMS) program; this initiative was designed to provide greater access and support to academically talented students from economically disadvantaged backgrounds. Originally intended to provide financial support to lower income students, this NSF program also advocated that additional professional development and advising would be strategies to increase undergraduate persistence to graduation. This innovative program for economically disadvantaged students was extended in 2004 to include students from other disciplines including the physical and life sciences as well as the technology fields, and the new name of the program was Scholarships for Science, Technology, Engineering and Mathematics (S-STEM). The implementation of these two programs in Louisiana State University (LSU) has shown significant and measurable success since 2000, making LSU a Model University in providing support to economically disadvantaged students within the STEM disciplines. The achievement of these programs is evidenced by the graduation rates of its participants. This report provides details on the educational model employed through the CSEMS/S-STEM projects at LSU and provides a path to success for increasing student retention rates in STEM disciplines. While the LSU??s experience is presented as a case study, the potential relevance of this innovative mentoring program in conjunction with the financial support system is discussed in detail. 相似文献