• The KIPS Transactions:PartA
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• v.13A no.2 s.99
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• pp.123-136
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• 2006

The prefetching technique is an effective way to reduce the latency caused memory access. However, excessively aggressive prefetch not only leads to cache pollution so as to cancel out the benefits of prefetch but also increase bus traffic leading to overall performance degradation. In this thesis, a prefetch filtering scheme is proposed which dynamically decides whether to commence prefetching by referring a filtering table to reduce the cache pollution due to unnecessary prefetches In this thesis, First, prefetch hashing table 1bitSC filtering scheme(PHT1bSC) has been shown to analyze the lock problem of the conventional scheme, this scheme such as conventional scheme used to be N:1 mapping, but it has the two state to 1bit value of each entries. A complete block address table filtering scheme(CBAT) has been introduced to be used as a reference for the comparative study. A prefetch block address lookup table scheme(PBALT) has been proposed as the main idea of this paper which exhibits the most exact filtering performance. This scheme has a length of the table the same as the PHT1bSC scheme, the contents of each entry have the fields the same as CBAT scheme recently, never referenced data block address has been 1:1 mapping a entry of the filter table. On commonly used prefetch schemes and general benchmarks and multimedia programs simulates change cache parameters. The PBALT scheme compared with no filtering has shown enhanced the greatest 22%, the cache miss ratio has been decreased by 7.9% by virtue of enhanced filtering accuracy compared with conventional PHT2bSC. The MADT of the proposed PBALT scheme has been decreased by 6.1% compared with conventional schemes to reduce the total execution time.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.824-831
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• 2009

Purpose : We aimed to investigate the efficacy of and functional recovery after intracerebral transplantation of different doses of mouse mesenchymal stem cells (mMSCs) in immature rat brain with hypoxic-ischemic encephalopathy (HIE). Methods : Postnatal 7-days-old Sprague-Dawley rats, which had undergone unilateral HI operation, were given stereotaxic intracerebral injections of either vehicle or mMSCs and then tested for locomotory activity in the 2nd, 4th, 6th, and 8th week of the stem cell injection. In the 8th week, Morris water maze test was performed to evaluate the learning and memory dysfunction for a week. Results : In the open field test, no differences were observed in the total distance/the total duration (F=0.412, P=0.745) among the 4 study groups. In the invisible-platform Morris water maze test, significant differences were observed in escape latency (F=380.319, P<0.01) among the 4 groups. The escape latency in the control group significantly differed from that in the high-dose mMSC and/or sham group on training days 2-5 (Scheffe's test, P<0.05) and became prominent with time progression (F=6.034, P<0.01). In spatial probe trial and visible-platform Morris water maze test, no significant improvement was observed in the rats that had undergone transplantation. Conclusion : Although the rats that received a high dose of mMSCs showed significant recovery in the learning-related behavioral test only, our data support that mMSCs may be used as a valuable source to improve outcome in HIE. Further study is necessary to identify the optimal dose that shows maximal efficacy for HIE treatment.

• The Korean Journal of Food And Nutrition
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• v.19 no.1
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• pp.62-69
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• 2006

This study was performed to investigate the biocogical activity of the phospholipid separated and purified from duck egg yolk as functional brain food. A quantitative restriction of maternal diet was given to Sprague-Dawely rats during lactation. Animals were separated into three groups, such as control, duck egg phospholipid(PL) or pig-brain phospholipid additions groups. And ad libitum during lactation was given to control groups. All of the offsprings at 3 weeks of age fed a diet ad libitum for 4 weeks of rehabilitation. Body weight and brain weight and protein, phosphplipid, and cholesterol were determined on offsprings of each of group sacrificed at 0, 1, 2, 3, 5 and 7 weeks of age, sacrified body weight of duck egg phospholipid and pig brain phospholipid group were significantly higher than the control group. Body weight and brain weight after a recovery period were significantly at the control group. However, protein, phospholipid and cholesterol contents were significantly high than the control group. Response latency in the passive avoidance task was the lowest in the ${\beta}$-amyloid group and highest in the phospholipid group. It is consequently suggested that phospholipid supplement may be effective in memory improvement.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.8
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• pp.719-729
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• 2000

Prefetching aims at reducing memory latency by fetching, in advance, data that are likely to be requested by the processor in a near future. The effectiveness of prefetching is determined by how accurate the prediction on the needed instructions and data is. Most previous studies on prefetching were limited to proposing a particular prefetch scheme and its performance evaluation, paying little attention to theoretical aspects of prefetching. This paper focuses on the theoretical aspects of instruction prefetching. For this purpose, we propose a clairvoyant prefetch model that makes use of perfect history information. Based on this theoretical model, we analyzed upper limits on the prefetch prediction accuracies of the SPEC benchmarks. The results show that the prefetch prediction accuracy is very high when there is no cache. However, as the size of the instruction cache increases, the prefetch prediction accuracy drops drastically. For example, in the case of the spice benchmark, the prefetch prediction accuracy drops from 53% to 39% when the cache size increases from 2Kbyte to 16Kbyte (assuming 16byte block size). These results indicate that as the cache size increases, most localities are captured by the cache and that instruction prefetching based on the information extracted from the references that missed in the cache suffers from prediction inaccuracies

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1178-1191
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• 2008

This experiment was designed to investigate the effect of the SSJHT hot water extract & ultra-fine Powder on Alzheimer's Disease Model Induced by ${\beta}A$. The effects of the SSJHT hot water extract on expression of IL-1RA, $IL-1{\beta}$$, IL-6, IL-10, $TNF-{\alpha}$, NOS-II, COX-2 mRNA and production of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ in BV2 microglial cell line treated by lipopolysacchaide(LPS). The effects of the SSJHT hot water extract & ultra-fine powder on (1) the behavior (2) expression of $IL-1{\beta}$, $TNF-{\alpha}$, MDA, CD68, CD11b and AChE (3) and the infarction area of the hippocampus in Alzheimer's diseased mice induced with ${\beta}A$ were investigated. The SSJHT hot water extract suppressed the expression of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$, NOS-II, COX-2 mRNA and increased IL-1RA, IL-10 in BV2 microglia cell line treated with LPS. The SSJHT hot water extract suppressed the production of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ significantly in BV2 microglial cell line treated with LPS. The SSJHT hot water extract & ultra-fine powder a significant inhibitory effect on the memory deficit was shown for the mice with Alzheimer's disease induced by ${\beta}A$ in the Morris water maze experiment, which measured step-through latency. The SSJHT hot water extract & ultra-fine powder suppressed the expression of $TNF-{\alpha}$$, $L-1{\beta}$ protein significantly in the microglial cell of mice with Alzheimer's disease induced by ${\beta}A$. The SSJHT hot water extract & ultra-fine powder reduced the MDA and suppressed the over-expression of CD68, CD11b in the mice with Alzheimer's disease induced by ${\beta}A$. The SSJHT hot water extract & ultra-fine powder significantly decreased AChE activity in the serum of the mice with Alzheimer's disease induced by ${\beta}A$. The SSJHT hot water extract & ultra-fine powder reduced infarction area of hippocampus. and controlled the injury of brain tissue in the mice with Alzheimer's disease induced by ${\beta}A$. The results suggest that the SSJHT hot water extract & ultra-fine powder may be effective for treatment of Alzheimer's disease. Investigation into the clinical use of the SSJHT hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

• Journal of Life Science
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• v.19 no.7
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• pp.917-922
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• 2009

The effect of adding docosahexaenoic acid into an n-3 fatty acid adequate diet on the improvement of learning related brain function was investigated. On the second day after conception, Sprague Dawley strain dams were subjected to a diet containing either n-3 fatty acid adequate (Adq, 3.4% linolenic acid) or n-3 fatty acid adequate+docosahexaenoic acid (Adq+DHA, 3.31%linolenic acid plus 9.65% DHA). After weaning, male pups were fed on the same diet of their respective dams until adulthood. Motor activity and Morris water maze tests were measured at 10 weeks. In the motor activity test, there were no statistically significant differences in moving time and moving distance between the Adq and Adq+DHA diet groups. The n-3 fatty acid adequate with DHA (Adq+DHA) group tended to show a shorter escape latency, swimming time and swimming distance compared to the n-3 fatty acid adequate group (Adq), but the differences were not statistically significant. There was no difference in resting time, but the Adq+DHA group showed a higher swimming speed compared to the Adq group. In memory retention trials, the numbers of crossing of the platform position (region A), in which the hidden platform was placed, were significantly greater than those of other regions for both Adq and Adq+DHA groups. Based on these results, adding DHA into the n-3 fatty acid adequate diet from gestation to adulthood tended to induce better spatial learning performance in Sprague Dawley rats as assessed by the Morris water maze test, although the difference was not significant.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.688-699
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• 2007

This experiment was designed to investigate the effect of the SST hot water extract & ultra-fine Powder on Alzheimer's Disease Model Induced by ${\beta}$A. The effects of the SST hot water extract on expression of IL-1${\beta}$, IL-6, TNF-${\alpha}$, NOS-II, COX-2 mRNA and production of IL-l${\beta}$, IL-6, TNF-${\alpha}$, NO in BV2 microglial cell line treated by lipopolysacchaide(LPS). The effects of the SST hot water extract & ultra-fine powder on (1) the behavior (2) expression of IL-1${\beta}$, TNF-${\alpha}$, MDA, (3) Glucose, AChE in serum (4) the infarction area of the hippocampus, and brain tissue injury in Alzheimer's diseased mice induced with ${\beta}$A were investigated. The SST hot water extract suppressed the expression of IL-1${\beta}$, IL-6 and TNF-a mRNA ${\alpha}$in BV2 microglia cell line treated with LPS. The SST hot water extract suppressed the production of IL-1${\beta}$, IL-6, TNF-${\alpha}$, NO in BV2 microglial cell line treated with LPS. The SST hot water extract & ultra-fine powder a significant inhibitory effect on the memory deficit was shown for the mice with Alzheimer's disease induced by ${\beta}$A in the Morris water maze experiment, which measured stop-through latency. The SST ultra-fine powder suppressed the expression of TNF-a protein significantly in the microglial cell of mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced the MDA and suppressed the over-expression of CD68, CD11b in the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder decreased AChE significantly in the serum of the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced infarction area of hippocampus, and controlled the injury of brain tissue in the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced the tau protein, GFAP, and presenilin1, 2 of hippocampus in the mice with Alzheimer's disease induced by ${\beta}$A. These results suggest that the SST hot water extract & ultra-fine powder may be effective for the prevention and treatment of A1zheimer's disease. Investigation into the clinical use of the SST hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.3
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• pp.72-83
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• 2017

GPUs can provide high throughput with latency hiding by executing many warps in parallel. MSHR(Miss Status Holding Registers) for L1 data cache tracks cache miss requests until required data is serviced from lower level memory. In recent GPUs, excessive requests for cache resources cause underutilization problem of GPU resources due to cache resource reservation fails. In this paper, we propose a new warp scheduling technique to reduce stall cycles under MSHR resource shortage. Cache miss rates for each warp is predicted based on the observation that each warp shows similar cache miss rates for long period. The warps showing low miss rates or computation-intensive warps are given high priority to be issued when MSHR is full status. Our proposal improves GPU performance by utilizing cache resource more efficiently based on cache miss rate prediction and monitoring the MSHR entries. According to our experimental results, reservation fail cycles can be reduced by 25.7% and IPC is increased by 6.2% with the proposed scheduling technique compared to loose round robin scheduler.

• Journal of Korean Neurosurgical Society
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• v.67 no.3
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• pp.333-344
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• 2024

Objective : Markers of neuroinflammation during ischemic stroke are well characterized, but additional markers of neural damage are lacking. The study identified associations of behavioral disorders after stroke with histologic neural damage and molecular biological change. Methods : Eight-week-old, 25 g male mice of the C57BL/6J strain were subjected to middle cerebral artery occlusion (MCAO) to induce ischemic stroke. The control group was a healthy wild type (WT), and the experimental group were designed as a low severity MCAO1 and a high severity MCAO2 based on post-stroke neurological scoring. All groups underwent behavioral tests, realtime polymerase chain reaction, triphenyltetrazolium chloride (TTC) staining and Hematoxylin and Eosin staining. One-way analysis of variance was used to analyze statistical significance between groups. Results : In TTC staining, MCAO1 showed 29.02% and MCAO2 showed 38.94% infarct volume (p<0.0001). The pro-inflammatory cytokine interleukin (IL)-1β was most highly expressed in MCAO2 (WT 0.44 vs. MCAO1 2.69 vs. MCAO2 5.02, p<0.0001). From the distance to target in the Barnes maze test, WT had a distance of 178 cm, MCAO1 had a distance of 276 cm, and MCAO2 had a distance of 1051 (p=0.0015). The latency to target was 13.3 seconds for WT, 27.9 seconds for MCAO1, and 87.9 seconds for MCAO2 (p=0.0007). Prospero homeobox 1 (Prox1) was most highly expressed in MCAO2 (p=0.0004). Doublecortin (Dcx) was most highly expressed in MCAO2 (p<0.0001). Conclusion : The study demonstrated that histological damage to neural cells and changes in brain mRNA expression were associated with behavioral impairment after ischemic stroke. Prox1 and Dcx may be biomarkers of neural damage associated with long-term cognitive decline, and increased expression at the mRNA level was consistent with neural damage and long-term cognitive dysfunction.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.459-467
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• 2009

Purpose: The maximum likelihood-expectation maximization (ML-EM) is the statistical reconstruction algorithm derived from probabilistic model of the emission and detection processes. Although the ML-EM has many advantages in accuracy and utility, the use of the ML-EM is limited due to the computational burden of iterating processing on a CPU (central processing unit). In this study, we developed a parallel computing technique on GPU (graphic processing unit) for ML-EM algorithm. Materials and Methods: Using Geforce 9800 GTX+ graphic card and CUDA (compute unified device architecture) the projection and backprojection in ML-EM algorithm were parallelized by NVIDIA's technology. The time delay on computations for projection, errors between measured and estimated data and backprojection in an iteration were measured. Total time included the latency in data transmission between RAM and GPU memory. Results: The total computation time of the CPU- and GPU-based ML-EM with 32 iterations were 3.83 and 0.26 see, respectively. In this case, the computing speed was improved about 15 times on GPU. When the number of iterations increased into 1024, the CPU- and GPU-based computing took totally 18 min and 8 see, respectively. The improvement was about 135 times and was caused by delay on CPU-based computing after certain iterations. On the other hand, the GPU-based computation provided very small variation on time delay per iteration due to use of shared memory. Conclusion: The GPU-based parallel computation for ML-EM improved significantly the computing speed and stability. The developed GPU-based ML-EM algorithm could be easily modified for some other imaging geometries.