Sungkyunkwan University

About: Sungkyunkwan University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Graphene. The organization has 28229 authors who have published 56428 publications receiving 1352733 citations. The organization is also known as: 성균관대학교.

Design of flash-based DBMS: an in-page logging approach

Abstract: The popularity of high-density flash memory as data storage media has increased steadily for a wide spectrum of computing devices such as PDA's, MP3 players, mobile phones and digital cameras. More recently, computer manufacturers started launching new lines of mobile or portable computers that did away with magnetic disk drives altogether, replacing them with tens of gigabytes of NAND flash memory. Like EEPROM and magnetic disk drives, flash memory is non-volatile and retains its contents even when the power is turned off. As its capacity increases and price drops, flash memory will compete more successfully with lower-end, lower-capacity disk drives. It is thus not inconceivable to consider running a full database system on the flash-only computing platforms or running an embedded database system on the lightweight computing devices. In this paper, we present a new design called in-page logging (IPL) for flash memory based database servers. This new design overcomes the limitations of flash memory such as high write latency, and exploits unique characteristics of flash memory to achieve the best attainable performance for flash-based database servers. We show empirically that the IPL approach can yield considerable performance benefit over traditional design for disk-based database servers. We also show that the basic design of IPL can be elegantly extended to support transactional database recovery.

Finding needles in haystacks: Linking scientific names, reference specimens and molecular data for Fungi

Abstract: DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.

International consensus on (ICON) pediatric asthma

Abstract: Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals

Abstract: High-quality and millimeter-sized perovskite single crystals of CsPbBr3 and Cs4PbBr6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs4PbBr6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr3, which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr6]4– octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.