• Spatial Information Research
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• v.20 no.5
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• pp.67-76
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• 2012

Recently the mobile DBMS (Database Management System) is popular to store and manage large data in a mobile device. Especially, the research and development about mobile storage structure and querying method for navigation map data in a mobile device have been performed. The performance of the mobile DBMS in which random data accesses are most queries if the NAND flash memory is used as storage media of the DBMS is degraded. The reason is that the performance of flash memory is good in writing sequentially but bad in writing randomly as the features of the NAND flash memory. So, new storage structure and querying policies of the mobile DBMS are needed in the mobile DBMS in which a flash memory is used as storage media. In this paper, we have studied the policy of the database page management to enhance the performance of the frequent random update and applied this policy to the navigation-specialized mobile DBMS which supports incremental map update. And also we have evaluated the performance of this policy by experiments.

• Animal cells and systems
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• v.16 no.4
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• pp.302-312
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• 2012

The purpose of this study was to examine whether Phellodendri Cortex extract (PCE) could improve learning and memory impairments caused by lipopolysaccharide (LPS)-induced inflammation in the rat brain. The effect of PCE on modulating pro-inflammatory mediators in the hippocampus and its underlying mechanism were investigated. Injection of LPS into the lateral ventricle caused acute regional inflammation and subsequent deficits in spatial learning ability in the rats. Daily administration of PCE (50, 100, and 200 mg/kg, i.p.) for 21 days markedly improved the LPS-induced learning and memory disabilities in the Morris water maze and passive avoidance test. PCE administration significantly decreased the expression of pro-inflammatory mediators such as tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, and cyclooxygenase-2 mRNA in the hippocampus, as assessed by RT-PCR analysis and immunohistochemistry. Together, these findings suggest that PCE significantly attenuated LPS-induced spatial cognitive impairment through inhibiting the expression of pro-inflammatory mediators in the rat brain. These results suggested that PCE may be effective in preventing or slowing the development of neurological disorders, including Alzheimer's disease, by improving cognitive and memory function because of its anti-inflammation activity in the brain.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.2
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• pp.85-89
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• 2009

Puerariae flos (PF) is a traditional oriental medicinal plant and has clinically been prescribed for a long time. The purpose of the present study was to examine the effect of PF on repeated stress-induced alterations of learning and memory on a Morris water maze (MWM) test in ovariectomized (OVX) female rats. The changes in the reactivity of the cholinergic system were assessed by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) in the hippocampus after behavioral testing. The female rats were randomly divided into four groups: the nonoperated and nonstressed group (normal), the sham-operated and stressed group (control), the ovariectomized and stressed group (OS), and the ovariectomized, stressed and PF treated group (OSF). Rats were exposed to immobilization stress (IMO) for 14 d (2 h/d), and PF (400 mg/kg, p.o.) was administered 30 min before IMO stress. Results showed that treatments with PF caused significant reversals of the stress-induced deficits in learning and memory on a spatial memory task, and also increased the ChA T immunoreactivities. In conclusion, administration of PF improved spatial learning and memory in OVX rats, and PF may be useful for the treatment of postmenopausal-related dementia.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.54-61
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• 2009

This paper presents a new electromyogram (EMG) pattern recognition method based on the Hierarchical Temporal Memory (HTM) algorithm which is originally devised for image pattern recognition. In the modified HTM algorithm, a simplified two-level structure with spatial pooler, temporal pooler, and supervised mapper is proposed for efficient learning and classification of the EMG signals. To enhance the recognition performance, the category information is utilized not only in the supervised mapper but also in the temporal pooler. The experimental results show that the ten kinds of hand motion are successfully recognized.

• Journal of Korean Association for Spatial Structures
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• v.22 no.4
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• pp.39-48
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• 2022

The energy dissipation of inverted V-type eccentric steel braced frames can be achieved through the yielding of a slit link, through yielding of a number of strips between slits when the frame is subjected to inelastic cyclic deformation. On the other hand, the development of seismic resistance system without residual deformation is obtained by applying the superelasdtic shape memory alloy (SMA) material into the brace and link elements. This paper presents results from a systematic three-dimensional nonlinear finite element analysis on the structural behavior of the eccentric bracing systems subjected to cyclic loadings. A wide scope of structural behaviors explains the horizontal stiffness, hysteretic behaviors, and failure modes of the recentering eccentric bracing system. The accurate results presented here serve as benchmark data for comparison with results obtained using modern experimental testing and alternative theoretical approaches.

• Spatial Information Research
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• v.23 no.3
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• pp.45-54
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• 2015

Since the V-World, the Spatial Information Open Platform service, has started in 2012, a lot of people have increased explosively every year with their interest. It is necessary to know the specific service status in order to serve as indicators of the improvement of user's environment and the service to be added in the future based on the user's increasing need. However, there is difficulty to figure out more specific service status, such as the usage of hardware resources for 2D / 3D / Portal services and the actual user usage patterns, because the current system does not have the real-time monitoring system. Therefore, in this paper, through the analysis of the usage of system resources for 2D / 3D / Portal services based on web server log and the usage of hardware resources such as CPU, Memory based on system log, we analyze the usage of service in 2015 and compare with the results of the 2014, to present problems of the current system and the solutions about the problems.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.8
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• pp.181-188
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• 2016

Recently, as the amount of spatial information increases, an interest in the study of spatial information processing has been increased. Spatial database systems extended from the traditional relational database systems are difficult to handle large data sets because of the scalability. SpatialHadoop extended from Hadoop system has a low performance, because spatial computations in SpationHadoop require a lot of write operations of intermediate results to the disk, resulting in the performance degradation. In this paper, Spatial Computation Spark(SC-Spark) is proposed, which is an in-memory based distributed processing framework. SC-Spark is extended from Spark in order to efficiently perform the spatial operation for large-scale data. In addition, SC-Spark based on the GPGPU is developed to improve the performance of the SC-Spark. SC-Spark uses the advantage of the Spark holding intermediate results in the memory. And GPGPU-based SC-Spark can perform spatial operations in parallel using a plurality of processing elements of an GPU. To verify the proposed work, experiments on a single AMD system were performed using SC-Spark and GPGPU-based SC-Spark for Point-in-Polygon and spatial join operation. The experimental results showed that the performance of SC-Spark and GPGPU-based SC-Spark were up-to 8 times faster than SpatialHadoop.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.9
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• pp.70-76
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• 1998

By controlling the pixel of a LCD spatial light modulator electronically, we made a real-time moving window passing through the light on a LCD spatial light modulator. By using this LCD moving window, we suggested an angular multiplexed holographic memory system and in case of windows of 10$\times$10 pixels and 2$\times$2 pixels the total numbers of address are 1,536 and 38,400, respectively. To demonstrate the feasibility of the proposed method, we recorded and reconstructed 30 images by 30 input addresses.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.304.3-305
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• 2002

The present study investigated the passive avoidance and spatial learning in the ${\mu}$-opioid receptor gene knockout mice and wild type mice. In the step-through passive avoidance task. the ${\mu}$-opioid receptor knockout mice did not differ from the wild type mice. In Morris water maze. however. the ${\mu}$-opioid receptor knockout mice showed significant memory deficit compared to wild type mice. (omitted)

• Journal of Korean Association for Spatial Structures
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• v.20 no.3
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• pp.53-61
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• 2020

This paper presents a systematic numerical analysis to obtain the re-centering and energy dissipation capacities of Chevron braced steel frames subjected to seismic loadings. In order to develop a recentering seismic resistance system excluding a residual deformation, the chevron braced steel frames are assembled using super-elastic SMA (Shape Memory Alloy) braces. The three-dimensional nonlinear finite element models are constructed to investigate the horizontal stiffness, hysteretic behaviors, and failure modes of the re-centering Chevron bracing system.