• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.1-8
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• 2019

In this paper, we propose a performance isolation of shared space for virtualized SSD based storage systems, to solve the weakness in a VSSD framework. The proposed scheme adopts a CFQ scheduler and a shared space-based FTL for the fairness and the performance isolation for multiple users on virtualized SSD based storage systems. Using the CFQ scheduler, we ensure SLOs for the storage systems such as a service time, a allocated space, and a IO latency for users on the virtualized storage systems. In addition, to improve a throughput and reduce a computational latency for garbage collection, a shared space-based FTL is adopted to maintain the information of SLOs for users and it manages shared spaces among the users. In our experiments, the proposal improved the throughput of garbage collection by 7.11%, on average, and reduced the computational latency for garbage collection by 9.63% on average, compared to the previous work.

• Journal of the Korea Society of Computer and Information
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• v.24 no.7
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• pp.1-8
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• 2019

Recently, an SSD with hybrid buffer memories is actively researching to reduce the overall latency in server computing systems. However, existing hybrid buffer policies caused many swapping operations in pages because it did not consider the overall latency such as read/write operations of flash chips in the SSD. This paper proposes the clock with hybrid buffer memories (CLOCK-HBM) for a new hybrid buffer policy in the SSD with server computing systems. The CLOCK-HBM constructs new policies based on unique characteristics in both DRAM buffer and NVMs buffer for reducing the number of swapping operations in the SSD. In experimental results, the CLOCK-HBM reduced the number of swapping operations in the SSD by 43.5% on average, compared with LRU, CLOCK, and CLOCK-DNV.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.157-163
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• 2023

Recently, as businesses and data types become more complex and diverse, efficient data analysis using machine learning is required. However, since communication in the cloud environment is greatly affected by network latency, data analysis is not smooth if information delay occurs. In this paper, SPT (Safe Proper Time) was applied to the cluster-based machine learning data analysis agent proposed in previous studies to solve this delay problem. SPT is a method of remotely and directly accessing memory to a cluster that processes data between layers, effectively improving data transfer speed and ensuring timeliness and reliability of data transfer.

• Journal of Oriental Neuropsychiatry
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• v.10 no.1
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• pp.39-51
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• 1999

The effects of Hyangbujapalmultang on the enhancement of learning and memory of AD model rats were studied with Morris water maze. Sample group was electrolytically lesioned on nucleus basalis of Meynert(nbM), and then daily treated with the medicine for two months. Control group with nbM lesion, and sham group with the sham operation were treated the vehicle for the same duration. The following results were observed. 1. As the learning trials of Morris water maze were proceeded, sham group showed the escape latency from $54.7{\pm}2.28$ seconds in 1st trial to $13.3{\pm}3.27$ seconds in 7th. The control group showed the escape latency from $58.0{\pm}1.78$ seconds in 1st trial to $51.3{\pm}3.52$ seconds in 7th. The sample group showed the escape latency from $57.0{\pm}2.21$ seconds in 1st trial to $28.4{\pm}4.82$ seconds in 7th. Therefore, these data shows that all three groups were improved in learning capacity as trials were proceeded, but the sample group showed more prominent improvement in learning compared with the control group(p<0.05). 2. In memory retention test of Morris water maze that counts the staying time in the target area during 30 seconds of freely swimming period, sham group stayed for $4.81{\pm}1.15$ seconds, the control group stayed for $1.27\pm}0.78$ seconds, and the sample group stayed for $4.17{\pm}1.47$ seconds. The analysis of the memory retention data shows that the sample group marked more improvement in memory retention compared with the control group, but could not obtained statistically significant result(p<0.05). With the experimental results above, Hyangbujapalmultang can be supposed to have the improving effects on the learning of AD model rats induced by electrolytic lesion of nbM.

• International Journal of Contents
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• v.3 no.1
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• pp.19-23
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• 2007

Recently, several main-memory index structures have been proposed to reduce the impact of secondary cache misses. In mainmemory storage systems, secondary cache misses have a substantial effect on the performance of index structures. However, recent studies still stiffer from secondary cache misses when visiting each level of index tree. In this paper, we propose a new index structure that minimizes the total amount of cache miss latency. The proposed index structure prefetched grandchildren of a current node. The basic structure of the proposed index structure is based on that of the CSB+-Tree, which uses the concept of a node group to increase fan-out. However, the insert algorithm of the proposed index structure significantly reduces the cost of a split. The superiority of our algorithm is shown through performance evaluation.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.2
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• pp.79-86
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• 2019

For decades, in-memory data structures have been designed for DRAM-based main memory that provides symmetric read/write performances and has no limited write endurance. However, such data structures provide sub-optimal performance for NVM as it has different characteristics to DRAM. With this motivation, we rethink a conventional red-black tree in terms of its efficacy under NVM settings. The original red-black tree constantly rebalances sub-trees so as to export fast access time over dataset, but it inevitably increases the write traffic, adversely affecting the performance for NVM with a long write latency and limited endurance. To resolve this problem, we present a variant of the red-black tree called a hierarchical balanced binary search tree. The proposed structure maintains multiple keys in a single node so as to amortize the rebalancing cost. The performance study reveals that the proposed hierarchical binary search tree effectively reduces the write traffic by effectively reaping the high capacity of NVM.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.243-249
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• 2015

Myrrh, Angelicae Radix, and Schisandrae Fructus have been used to treat diverse diseases including neurological disorder in the traditional Korean medicine. In the present study, we investigated the ameliorating effects of HPM-1, a combined extract of Myrrh, Angelicae Radix and Schisandrae Fructus, on scopolamine-induced memory impairments in mice. First, we assessed HPM-1, HPM-2 and HPM-3, in which Myrrh was extracted with water, 30% ethanol, and 30% ethanol/3% vinegar, respectively. The oral administration of HPM-1, HPM-2, or HPM-3 significantly reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task. In the passive avoidance task, HPM-1 or HPM-3 restored the decreased latency time of the retention trial by scopolamine treatment, but in terms of efficacy, HPM-1 showed more beneficial effects than HPM-3. In addition, HPM-1 administration reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task and scopolamine-decreased latency time in the passive avoidance in a dose-dependent manner. These results suggest that HPM-1 has the therapeutic potential in memory impairments.

• The Journal of Pediatrics of Korean Medicine
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• v.19 no.2
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• pp.99-114
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• 2005

Objectives: This study was aimed to find out the anti-stress and protective-memory effect of Quibitanggagam(QBT) on stress of rats Methods : This experimental study was conducted with elevated plus maze test, passive avoidance test, morris water maze test, and consequently density of AchE reactivity in the CA1 of hippocampus to research the learning and memory of rats affected by restraint stress, Results: Passive avoidance test revealed that time latency of retention test for QBT+Stress group significantly decreased on 2, 3rd day. Morris water maze revealed that acqusitive ability of QBT+Stress group significantly improved on 2, 3rd day and retentive ability of QBT+Stress group was significantly improved on 7th day. Elevated plus maze test revealed that latency in open arm of QBT+Stress group significantly decreased and locomotor activity(number of entered arm) of QBT+Stress group was significantly increased. The values of density of AchE stained nuclei in the CA1 of hippocampus QBT+Stress group was significantly increased compared with SAL+Stress group. Conclusion : According to the above results, it is concluded that QBT will be useful as a remedy against stress disease and improving memory.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.821-830
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• 1997

The directory-based cache coherence scheme is an attractive approach to solve the caceh coherence problem in a large-scale shared-memory multiprocessor.However, the exsting directory-based schemes have some problens such as the enormous storage overhead for a directory, the long invalidation latency, the heavy network condes-tion, and the low scalability.For resolving these problems, we propose a new directroy- based caceh coherence scheme which is suitable for building scalable, shred-memory multiprocessors.In this scheme, each directory en-try ofr a given memory block is a number-balanced binaty tree(NBBT) stucture.The NBBT has several proper-ties to effciently maintain the directory for the cache consistency such that the shape is unique, the maximum depth is [log$_2$n], and the tree has the minimum number of leaf nodes among the binarry tree with n nodes.Therefore, this scheme can reduce the storage overhead, the network traffic, and the inbalidation latency and can ensutr the high- scalability the large-scale shared-memory multiprocessors.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.419-428
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• 2001

Advances in circuit and integration technology are continuously boosting the speed of processors. One of the main challenges presented by such developments is the effective use of powerful processors in shared memory multiprocessor system. We believe that the interconnection problem is not solved even for small scale shared memory multiprocessor, since the speed of shared buses is unlikely to keep up with the bandwidth requirements of new powerful processors. In the past few years, point-to-point unidirectional connection have emerged as a very promising interconnection technology. The single slotted ring is the simplest form point-to-point interconnection. The main limitation of the single slotted ring architecture is that latency of access increase linearly with the number of the processors in the ring. Because of this, we proposed the dual slotted ring as an alternative to single slotted ring for cache-based multiprocessor system. In this paper, we analyze the proposed dual slotted ring architecture using new snooping protocol and enforce simulation to compare it with single slotted ring.