A Logical Model and Data Placement Strategies for MEMS Storage Devices

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

System-reliability-based Disaster Resilience Evaluation of Cable-stayed Bridge under Fire Hazard Using Reliability-Redundancy Analysis

The 20th working conference of the IFIP Working Group 7.5 on Reliability and Optimization of Structural Systems (IFIP 2022) will be held at Kyoto University, Kyoto, Japan, September 19-20, 2022.The concept of disaster resilience recently emerged in efforts to gain holistic understanding of civil infrastructure systems exposed to various natural or human-made hazards. To effectively evaluate the resilience of complex infrastructure systems generally consisting of many interdependent structural components, Lim et al. (2022) proposed a system-reliability-based framework for disaster resilience. In the proposed framework, the disaster resilience of a civil infrastructure system is characterized by three criteria: reliability, redundancy, and recoverability. For comprehensive resilience analyses at the scale of individual structures, the reliability (β) and redundancy (π) indices were newly defined in the context of component- and system-level reliability analysis, respectively. Reliability-redundancy diagram, i.e., the scatter plot of the reliability and redundancy indices computed for each initial disruption scenario, was also proposed to help a decision-maker check whether the corresponding risk is acceptable for the society. In this paper, we demonstrate the framework through its application to a cable-stayed bridge in South Korea, the Seohae Grand Bridge under fire hazards. First, a probabilistic model is developed to describe the hazard of fire scenarios that may occur on the deck of the cable-stayed bridge. Next, finite element simulations are performed to compute the reliability and redundancy indices through component and system reliability analyses for the fire accident scenarios. An adaptive simulation method, AK-MCS (Echard et al. 2011), is employed to overcome the computational cost issue. The example successfully demonstrates that the reliability-redundancy analysis and diagram facilitate a comprehensive assessment of the disaster resilience of a complex civil infrastructure such as a cable-stayed bridge by using sophisticated computational simulations and advanced reliability methods

Climatic Controls on Spring Onset of the Tibetan Plateau Grasslands from 1982 to 2008

Understanding environmental controls on vegetation spring onset (SO) in the Tibetan Plateau (TP) is crucial to diagnosing regional ecosystem responses to climate change. We investigated environmental controls on the SO of the TP grasslands using satellite vegetation index (VI) from the 3rd Global Inventory Modeling and Mapping Studies (GIMMS3g) product, with in situ air temperature (Ta) and precipitation (Prcp) measurement records from 1982 to 2008. The SO was determined using a dynamic threshold method based on a 25% threshold of seasonal VI amplitude. We find that SO shows overall close associations with spring Ta, but is also subject to regulation from spring precipitation. In relatively dry but increasingly wetting (0.50 mm·year−1, p \u3c 0.10) grasslands (mean spring Prcp = 22.8 mm; Ta = −3.27 °C), more precipitation tends to advance SO (−0.146 day·mm−1, p = 0.150) before the mid-1990s, but delays SO (0.110 day·mm−1, p = 0.108) over the latter record attributed to lower solar radiation and cooler temperatures associated with Prcp increases in recent years. In contrast, in relatively humid TP grasslands (73.0 mm; −3.51 °C), more precipitation delays SO (0.036 day·mm−1, p = 0.165) despite regional warming (0.045 °C·year−1, p \u3c 0.05); the SO also shows a delaying response to a standardized drought index (mean R = 0.266), indicating a low energy constraint to vegetation onset. Our results highlight the importance of surface moisture status in regulating the phenological response of alpine grasslands to climate warming

GaAs droplet quantum dots with nanometer-thin capping layer for plasmonic applications

We report on the growth and optical characterisation of droplet GaAs quantum dots with extremely-thin (11 nm) capping layers. To achieve such result, an internal thermal heating step is introduced during the growth and its role in the morphological properties of the quantum dots obtained is investigated via scanning electron and atomic force microscopy. Photoluminescence measurements at cryogenic temperatures show optically stable, sharp and bright emission from single quantum dots, at near-infrared wavelengths. Given the quality of their optical properties and the proximity to the surface, such emitters are ideal candidates for the investigation of near field effects, like the coupling to plasmonic modes, in order to strongly control the directionality of the emission and/or the spontaneous emission rate, crucial parameters for quantum photonic applications.Comment: 1 pages, 3 figure

The Effectiveness of Moxibustion: An Overview During 10 Years

Moxibustion has been used to treat various types of disease. However, there is still insufficient evidence regarding its effectiveness. This study was performed to summarize and evaluate the effectiveness of moxibustion. A search was performed for all randomized controlled trials in PubMed between January 1998 and July 2008 with no language restriction. The results yielded 47 trials in which six moxibustion types were applied to 36 diseases ranging from breech presentation to digestive disorders. Moxibustion was compared to three types of control group: general care, Oriental medical therapies or waiting list. Moxibustion was superior to the control in 14 out of 54 control groups in 46 studies. There were no significant differences among groups in 7 studies, and the outcome direction was not determined in 33 studies. Seven studies were included in a meta-analysis. Moxibustion was more effective than medication in two ulcerative colitis studies (relative risk (95% CI), 2.20 (1.37, 3.52), P = .001, I2 = 0%). Overall, our results did not support the effectiveness of moxibustion in specific diseases due to the limited number and low quality of the studies and inadequate use of controls. In order to provide appropriate evidence regarding the effectiveness of moxibustion, more rigorous clinical trials using appropriate controls are warranted

History of Minimally Invasive Surgery for Gastric Cancer in Korea

Laparoscopic gastrectomy was begun in 1995 in Korea. But, there was 4 years gap to reactivate in 1999. High incidence of gastric cancer and increasing proportion of early cancer through national screening program along with huge effort and enthusiasm of laparoscopic gastric surgeon, and active academic exchange with Japanese doctors contributed development of laparoscopic gastrectomy in Korea. Study group activity of Korean Laparoscopic Gastrointestinal Surgery Study (KLASS) group and Collaborative Action for Gastric Cancer (COACT) group were paramount to evoke large scale multicenter clinical study and various well performed clinical studies. This review encompasses mainly international publications about this area so far in Korea

Effects of informative and confirmatory feedback on brain activation during negative feedback processing

The current study compared the effects of informative and confirmatory feedback on brain activation during negative feedback processing. For confirmatory feedback trials, participants were informed that they had failed the task, whereas informative feedback trials presented task relevant information along with the notification of their failure. Fourteen male undergraduates performed a series of spatial-perceptual tasks and received feedback while their brain activity was recorded. During confirmatory feedback trials, greater activations in the amygdala, dorsal anterior cingulate cortex, and the thalamus (including the habenular) were observed in response to incorrect responses. These results suggest that confirmatory feedback induces negative emotional reactions to failure. In contrast, informative feedback trials elicited greater activity in the dorsolateral prefrontal cortex (DLPFC) when participants experienced failure. Further psychophysiological interaction (PPI) analysis revealed a negative coupling between the DLPFC and the amygdala during informative feedback relative to confirmatory feedback trials. These findings suggest that providing task-relevant information could facilitate implicit down-regulation of negative emotions following failure