2,663 research outputs found
Accelerating Large-Scale Graph-based Nearest Neighbor Search on a Computational Storage Platform
K-nearest neighbor search is one of the fundamental tasks in various
applications and the hierarchical navigable small world (HNSW) has recently
drawn attention in large-scale cloud services, as it easily scales up the
database while offering fast search. On the other hand, a computational storage
device (CSD) that combines programmable logic and storage modules on a single
board becomes popular to address the data bandwidth bottleneck of modern
computing systems. In this paper, we propose a computational storage platform
that can accelerate a large-scale graph-based nearest neighbor search algorithm
based on SmartSSD CSD. To this end, we modify the algorithm more amenable on
the hardware and implement two types of accelerators using HLS- and RTL-based
methodology with various optimization methods. In addition, we scale up the
proposed platform to have 4 SmartSSDs and apply graph parallelism to boost the
system performance further. As a result, the proposed computational storage
platform achieves 75.59 query per second throughput for the SIFT1B dataset at
258.66W power dissipation, which is 12.83x and 17.91x faster and 10.43x and
24.33x more energy efficient than the conventional CPU-based and GPU-based
server platform, respectively. With multi-terabyte storage and custom
acceleration capability, we believe that the proposed computational storage
platform is a promising solution for cost-sensitive cloud datacenters.Comment: Extension of FCCM 20201 and Accepted in Transaction on Computer
The First Room-Temperature Ambient-Pressure Superconductor
For the first time in the world, we succeeded in synthesizing the
room-temperature superconductor ( K, 127C) working at
ambient pressure with a modified lead-apatite (LK-99) structure. The
superconductivity of LK-99 is proved with the Critical temperature (),
Zero-resistivity, Critical current (), Critical magnetic field (),
and the Meissner effect. The superconductivity of LK-99 originates from minute
structural distortion by a slight volume shrinkage (0.48 %), not by external
factors such as temperature and pressure. The shrinkage is caused by Cu
substitution of Pb(2) ions in the insulating network of Pb(2)-phosphate
and it generates the stress. It concurrently transfers to Pb(1) of the
cylindrical column resulting in distortion of the cylindrical column interface,
which creates superconducting quantum wells (SQWs) in the interface. The heat
capacity results indicated that the new model is suitable for explaining the
superconductivity of LK-99. The unique structure of LK-99 that allows the
minute distorted structure to be maintained in the interfaces is the most
important factor that LK-99 maintains and exhibits superconductivity at room
temperatures and ambient pressure
BIM-Based Construction Information Management Framework for Site Information Management
Projects in the construction industry are becoming increasingly large and complex, with construction technologies, methods, and the like developing rapidly. Various different types of information are generated by construction projects. Especially, a construction phase requires the input of many resources and generates a diverse set of information. While a variety of IT techniques are being deployed for information management during the construction phase, measures to create databases of such information and to link these various different types of information together are still insufficient. As such, this study aims to suggest a construction information database system based on BIM technology to enable the comprehensive management of site information generated during the construction phase. This study analyzed the information generated from construction sites and proposed a categorization system for structuring the generated information, along with a database model for storing such structured information. Through such efforts, it was confirmed that such a database system can be used for accumulating and using construction information; it is believed that, in the future, the continual accumulation and management of construction information will allow for corporate-level accumulation of knowledge as opposed to the individual accumulation of know-how
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Power-saving method for wireless sensor network
A power saving method of the present invention is provide for a wireless sensor network including a plurality of sensor nodes each transiting between a power saving mode and a transmit/receive mode, determines whether or not there is no transmit or receive data, enters the power saving mode if there is no transmit or receive data, and controls power consumption on the basis of signal-to-noise ratios in the power saving mode. In the power saving method of the present invention, it is possible to minimize the power consumption regardless of nodes density and without an adverse effect on the connectivity of the network, since the sojourn times of the sleep and idle states are determined adaptive to the interference level from neighboring nodes.Board of Regents, University of Texas Syste
Reinforcing effects of methamphetamine in an animal model of Attention-Deficit/Hyperactivity Disorder-the Spontaneously Hypertensive Rat
Substrains of the Spontaneously Hypertensive rat (SHR), a putative animal model of Attention-Deficit/Hyperactivity Disorder (ADHD), have demonstrated increased sensitivity to many drugs of abuse, including psychostimulants. Therefore, it was suggested that studies in SHR may help elucidate ADHD and comorbidity with substance use disorder (SUD). However, the drug intake profile of the SHR in the most relevant animal model of drug addiction, the self-administration (SA) test, and its response on the conditioned place preference (CPP) paradigm are not yet determined. In the present study, we employed SA and CPP tests to investigate the reinforcing effects of the psychostimulant methamphetamine in an SHR substrain obtained from Charles River, Japan (SHR/NCrlCrlj). Concurrent tests were also performed in Wistar rats, the strain representing "normal" heterogeneous population. To address if the presence of ADHD behaviors further increases sensitivity to the rewarding effect of methamphetamine during adolescence, a critical period for the onset of drug abuse, CPP tests were especially conducted in adolescent Wistar and SHR/NCrlCrlj. We found that the SHR/NCrlCrlj also acquired methamphetamine SA and CPP, indicating reinforcing effects of methamphetamine in this ADHD animal model. However, we did not observe increased responsiveness of the SHR/NCrlCrlj to methamphetamine in both SA and CPP assays. This indicates that the reinforcing effects of methamphetamine may be similar in strains and that the SHR/NCrlCrlj may not adequately model ADHD and increased sensitivity to methamphetamine
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