484 research outputs found

    Database Tuning and its Role in Information Technology Education

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    Course curriculum in database management systems encompasses many topics, from data modeling to implementation and testing. These topics establish a strong foundation for Information Technology students to analyze, design, and implement a database system. Beyond these basic skills, Information Technology students must be equipped with the necessary capabilities to address database performance issues, such as when end-user expectations are not met. The topic of database tuning includes various techniques associated with enhancing database performance, and is important in providing a well-rounded database curriculum, but this skill is not generally covered in most database management systems courses. Our study focuses on testing the researcher’s assumption that database tuning is not part of current Information Technology curriculums. In addition, its significance and importance in the curriculums is researched. We surveyed academics and professionals to quantify the importance of database tuning and establish an understanding of its role within the education of students taking database related courses

    MIS Research Involving Human Subjects: Processes and IRB Requirements

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    This paper discusses major issues and institutional requirements for human subjects\u27 research. In particular, it considers the responsibilities of principal investigators or individual researchers conducting human subjects research in management information systems. The paper introduces the issues related to human subjects\u27 research and presents the background and responsibilities of institutional review boards. An overview is presented of institutional review boards as they relate to management information systems within the broader context of social and behavioral science research. The data collection instruments commonly used in management information systems studies are considered in relation to human subject involvement. New developments such as the Internet as a mechanism for data collection are also considered

    Mitochondrial genomes of twelve species of hyperdiverse Trigonopterus weevils

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    Mitochondrial genomes of twelve species of Trigonopterus weevils are presented, ten of them complete. We describe their gene order and molecular features and test their potential for reconstructing the phylogeny of this hyperdiverse genus comprising > 1,000 species. The complete mitochondrial genomes examined herein ranged from 16,501 bp to 21,007 bp in length, with an average AT content of 64.2% to 69.7%. Composition frequencies and skews were generally lower across species for atp6, cox1-3, and cob genes, while atp8 and genes coded on the minus strand showed much higher divergence at both nucleotide and amino acid levels. Most variation within genes was found at the codon level with high variation at third codon sites across species, and with lesser degree at the coding strand level. Two large non-coding regions were found, CR1 (between rrnS and trnI genes) and CR2 (between trnI and trnQ), but both with large variability in length; this peculiar structure of the non-coding region may be a derived character of Curculionoidea. The nad1 and cob genes exhibited an unusually high interspecific length variation of up to 24 bp near the 3′ end. This pattern was probably caused by a single evolutionary event since both genes are only separated by trnS2 and length variation is extremely rare in mitochondrial protein coding genes. We inferred phylogenetic trees using protein coding gene sequences implementing both maximum likelihood and Bayesian approaches, each for both nucleotide and amino acid sequences. While some clades could be retrieved from all reconstructions with high confidence, there were also a number of differences and relatively low support for some basal nodes. The best partition scheme of the 13 protein coding sequences obtained by IQTREE suggested that phylogenetic signal is more accurate by splitting sequence variation at the codon site level as well as coding strand, rather than at the gene level. This result corroborated the different patterns found in Trigonopterus regarding to A+T frequencies and AT and GC skews that also greatly diverge at the codon site and coding strand levels.This work was funded by the German Academic Exchange Service DAAD (91654661 to Raden P. Narakusumo), and the German Research Foundation DFG (RI 1817/3-4 to Alexander Riedel). Part of the fieldwork for this study was funded by DIPA KSK Pengembangan Database KEHATI PDII LIPI 2018 and the collaborative project between LIPI and UC Berkeley (NSF Award #1457845)

    Cross-Identification Performance from Simulated Detections: GALEX and SDSS

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    We investigate the quality of associations of astronomical sources from multi-wavelength observations using simulated detections that are realistic in terms of their astrometric accuracy, small-scale clustering properties and selection functions. We present a general method to build such mock catalogs for studying associations, and compare the statistics of cross-identifications based on angular separation and Bayesian probability criteria. In particular, we focus on the highly relevant problem of cross-correlating the ultraviolet Galaxy Evolution Explorer (GALEX) and optical Sloan Digital Sky Survey (SDSS) surveys. Using refined simulations of the relevant catalogs, we find that the probability thresholds yield lower contamination of false associations, and are more efficient than angular separation. Our study presents a set of recommended criteria to construct reliable cross-match catalogs between SDSS and GALEX with minimal artifacts.Comment: 7 pages, 9 figures; ApJ in pres

    A Survey on Modality Characteristics, Performance Evaluation Metrics, and Security for Traditional and Wearable Biometric Systems

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    Biometric research is directed increasingly towards Wearable Biometric Systems (WBS) for user authentication and identification. However, prior to engaging in WBS research, how their operational dynamics and design considerations differ from those of Traditional Biometric Systems (TBS) must be understood. While the current literature is cognizant of those differences, there is no effective work that summarizes the factors where TBS and WBS differ, namely, their modality characteristics, performance, security and privacy. To bridge the gap, this paper accordingly reviews and compares the key characteristics of modalities, contrasts the metrics used to evaluate system performance, and highlights the divergence in critical vulnerabilities, attacks and defenses for TBS and WBS. It further discusses how these factors affect the design considerations for WBS, the open challenges and future directions of research in these areas. In doing so, the paper provides a big-picture overview of the important avenues of challenges and potential solutions that researchers entering the field should be aware of. Hence, this survey aims to be a starting point for researchers in comprehending the fundamental differences between TBS and WBS before understanding the core challenges associated with WBS and its design

    Neutron Stars—Cooling and Transport

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    Observations of thermal radiation from neutron stars can potentially provide information about the states of supranuclear matter in the interiors of these stars with the aid of the theory of neutron-star thermal evolution. We review the basics of this theory for isolated neutron stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.The work of A.P. on the effects of strong magnetic fields on blanketing envelopes (Sect. 5.2 and Appendix B) has been supported by the Russian Science Foundation (grant 14-12-00316)

    Effects of Job Accessibility Improved by Public Transport System: Natural Experimental Evidence from the Copenhagen Metro

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    This study examines the effect of accessibility to urban jobs via a public transport system on individual earnings and commuting behaviour. The effect of improved public transport based accessibility on these outcomes is determined by exploiting the exogenous variation in access to a public rail and Metro system resulting from the construction of a new terminal Metro station connecting southern townships to Copenhagen city centre. The results show that public transport based job accessibility has a positive and permanent effect on individual earnings. The increase in earnings is associated with a change in commuting patterns as the improved access to public transport facilitates a shift from employment within the township to better paid jobs in the city centre, as well as in other suburbs of the Copenhagen Metropolitan area
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