758 research outputs found

    A Logical Model and Data Placement Strategies for MEMS Storage Devices

    Full text link
    MEMS storage devices are new non-volatile secondary storages that have outstanding advantages over magnetic disks. MEMS storage devices, however, are much different from magnetic disks in the structure and access characteristics. They have thousands of heads called probe tips and provide the following two major access facilities: (1) flexibility: freely selecting a set of probe tips for accessing data, (2) parallelism: simultaneously reading and writing data with the set of probe tips selected. Due to these characteristics, it is nontrivial to find data placements that fully utilize the capability of MEMS storage devices. In this paper, we propose a simple logical model called the Region-Sector (RS) model that abstracts major characteristics affecting data retrieval performance, such as flexibility and parallelism, from the physical MEMS storage model. We also suggest heuristic data placement strategies based on the RS model and derive new data placements for relational data and two-dimensional spatial data by using those strategies. Experimental results show that the proposed data placements improve the data retrieval performance by up to 4.0 times for relational data and by up to 4.8 times for two-dimensional spatial data of approximately 320 Mbytes compared with those of existing data placements. Further, these improvements are expected to be more marked as the database size grows.Comment: 37 page

    Take your time first, time your search later: How college students perceive time in Web searching

    Full text link
    This study explores people's perception of time during their Web searches. Time is a major component of the context for information behavior, but in empirical studies it has been implied rather than investigated explicitly. The data were collected from Web search experiments in which participants were asked to conduct searches on three given tasks under differing search time conditions. The paper reports on findings drawn primarily from the exit interviews of 45 undergraduate and graduate students on their perception of time in Web searching. Study results indicate that at the beginning of their searching activity, participants did not explicitly consider temporal issues. However, these issues usually surface with the passage of time, especially when searches fail to go as planned. Perception of time is closely entangled with familiarity and difficulty of search task. In general, participants enjoyed spending time in searching and were not excessively concerned about time constraints. On the other hand, participants' affective experiences were sometimes caused by temporal issues. In conclusion, the study results indicate that temporal issues interlace with other contextual and affective factors in the process of Web searching.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78317/1/1450460253_ftp.pd

    Advances in large PECVD processing technology up to Gen 11 for TFT LCD and OLED

    Get PDF
    Recent surging demands for larger (\u3e50ā€) TVs rapidly driving display processing technologies toward bigger substrate sizes up to 10m2 range. Meanwhile, high performance displays (OLED TV, iPad, iMac and 4K monitorsā€¦) have stretched a-Si mobility (85% LCD TVs in the world, supported recent starting of over a dozen largest TV factories worldwide Gen 8.5 and above, in particular enabled \u3e95% of advanced IGZO metal-oxide TFT display products including all latest OLED TVs, Apple iPads, iMac 5K or 4K displays, Microsoft Surface Pro 4, as well as major brand 4K or 8K monitors. Please click Additional Files below to see the full abstract

    The effect of ephedrine on intraoperative hypothermia

    Get PDF
    BACKGROUND: Prevention of intraoperative hypothermia has become a standard of operative care. Since ephedrine has a thermogenic effect and it is frequently used to treat hypotension during anesthesia, this study was designed to determine the effect of ephedrine on intraoperative hypothermia of patients who are undergoing spine surgery. METHODS: Twenty-four patients were randomly divided to receive an ephedrine (the ephedrine group, n = 12) or normal saline (the control group, n = 12) infusion for 2 h. The esophageal temperature (the core temperature), the index finger temperature (the peripheral temperature) and the hemodynamic variables such as the mean blood pressure and heart rate were measured every 15 minutes after the intubation. RESULTS: At the end of the study period, the esophageal temperature and hemodynamic variables were significantly decreased in the control group, whereas those in the ephedrine group were stably maintained. The index finger temperature was significantly lower in the ephedrine group compared to that in the control group, suggesting the prevention of core-to-peripheral redistribution of the heat as the cause of temperature maintenance. CONCLUSIONS: An intraoperative infusion of ephedrine minimized the decrease of the core temperature and it stably maintained the hemodynamic variables during spine surgery with the patient under general anesthesia.ope

    Insulin Secretion and Incretin Hormone Concentration in Women with Previous Gestational Diabetes Mellitus

    Get PDF
    BackgroundWe examined the change in the levels of incretin hormone and effects of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) on insulin secretion in women with previous gestational diabetes (pGDM).MethodsA 75-g oral glucose tolerance test (OGTT) was conducted on 34 women with pGDM. In addition, 11 women with normal glucose tolerance, matched for age, height and weight, were also tested. The insulin, GIP, GLP-1, and glucagon concentrations were measured, and their anthropometric and biochemical markers were also measured.ResultsAmong 34 women with pGDM, 18 had normal glucose tolerance, 13 had impaired glucose tolerance (IGT) and 1 had diabetes. No significant differences were found in GLP-1 concentration between the pGDM and control group. However, a significantly high level of glucagon was present in the pGDM group at 30 minutes into the OGTT. The GIP concentration was elevated at 30 minutes and 60 minutes in the pGDM group. With the exception of the 30-minute timepoint, women with IGT had significantly high blood glucose from 0 to 120 minutes. However, there was no significant difference in insulin or GLP-1 concentration. The GIP level was significantly high from 0 to 90 minutes in patients diagnosed with IGT.ConclusionGLP-1 secretion does not differ between pGDM patients and normal women. GIP was elevated, but that does not seem to induce in increase in insulin secretion. Therefore, we conclude that other factors such as heredity and environment play important roles in the development of type 2 diabetes

    Approximation of most penetrating particle size for fibrous filters considering Cunningham slip correction factor

    Get PDF
    In the estimation of the aerosol single fiber efficiency using fibrous filters, there is a size range, where the particles penetrate most effectively through the fibrous collectors, and corresponding minimum single fiber efficiency. For small particles in which the diffusion mechanism is dominant, the Cunningham slip correction factor (Cc) affects the single fiber efficiency and the most penetrating particle size (MPPS). Therefore, for accurate estimation, Cc is essential to be considered. However, many previous studies have neglected this factor because of its complexity and the associated difficulty in deriving the appropriate parameterization particularly for the MPPS. In this study, the expression for the MPPS, and the corresponding expression for the minimum single fiber efficiency are analytically derived, and the effects of Cc are determined. In order to accommodate the slip factor for all particle-size ranges, Cc is simplified and modified. Overall, the obtained analytical expression for the MPPS is in a good agreement with the exact solution

    Effect of collagen endometrial patch loaded with adipose-derived mesenchymal stem cells on endometrial regeneration in rats with a thin endometrium

    Get PDF
    BackgroundThis study aimed to investigate the effects of a collagen endometrial patch (EM patch) loaded with adipose-derived mesenchymal stem cells (ADSCs) on endometrial regeneration in a rat model with thin endometrium.Materials and methodsThin endometrium was induced in female rats and divided into treatment groups as outlined: control, group 1(G1), local injection of ADSCs into the uterus, group 2 (G2), an EM patch without ADSCs, group 3 (G3), and an EM patch loaded with ADSCs, group 4 (G4). The rats were euthanized at either two weeks or four weeks after modeling and treatment followed by histological and biochemical analyses to examine the regenerative effects on the injured endometrium.ResultsTransplantation of the ADSC-loaded EM patch significantly promoted endometrial proliferation and increased the luminal epithelial area. Two weeks after treatment, the mean number of von Villebrand factor (vWF)+ or cluster of differentiation (CD) 31+-stained blood vessels was significantly higher in G4 than in G1 and G2. The mRNA and protein expression levels of TGF-Ī² and FGF2 were significantly upregulated in G4 compared to those in the control. G4 exhibited significantly increased LIF mRNA levels and immunoreactivity compared with the other groups at both two weeks and four weeks after treatment. Cell tracking after ADSCs treatment revealed the presence of a substantial number of ADSCs grafted in the uterine tissues of G4, whereas a low number of ADSCs that were focally clustered were present in G2.ConclusionTransplantation of EM patches loaded with ADSCs resulted in the histological and biochemical restoration of an injured endometrium. The strategic integration of EM patches and ADSCs holds significant promise as an innovative therapeutic approach for effectively treating impaired endometrial conditions
    • ā€¦
    corecore