• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.3
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• pp.8-14
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• 2012

In this paper, a low-area FFT structure using $Radix-4^2$ algorithm is proposed. The large point FFT structure consists of cascade connection of the many stages. In implementation of large point FFT using $Radix-4^2$ algorithm, stages which number of different coefficients are only 3 appear in every 2 stages. For example, in the 4096-point FFT, the stages that number of different coefficients are 3 appear in stage 1, 3, and 5 among 6 stages. Multiplication block area of these 3 stages can be reduced using CSD(Canonic Signed Digit) and common sub-expression sharing techniques. Using the proposed structure, the 256-point FFT is implemented with the Verilog-HDL coding and synthesized by $1.971mm^2$ cell area in tsmc $0.18{\mu}m$CMOS library. This result shows 23% cell area reduction compared with the conventional structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3715-3722
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• 2011

This paper presents a new Boolean extraction technique for logic synthesis. This method first calculates divisor/2-cube quotients, 2-cube quotient pairs, and 2-cube quotient matrices. Then we find candidates, which can be common sub-expressions, from 2-cube quotients and matrices. Next, candidate intersection provides the common sub-expressions for several logic expressions. Experimental results show the improvements in literal counts over the previous methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.2
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• pp.31-38
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• 2012

In this paper, a low area timing synchronization structure for the IEEE 802.11a OFDM MODEM SoC is proposed. The timing synchronization block of the IEEE 802.11a OFDM MODEM SoC requires large implementation area. In the proposed timing synchronization structure, it is shown that the number of multiplication can be reduced by using the transposed direct form filter. Furthermore, implementation area of the proposed structure can be more reduced using CSD(Canonic Signed Digit) and Common Sub-expression Sharing techniques. Through Verilog-HDL coding and synthesis, it is shown that the 22.7 % of implementation area can be reduced compared with the conventional one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1387-1394
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• 2011

In this paper, a low-area symbol timing offset synchronization structure for WLAN Modem is proposed. Using CSD(Canonic Signed Digit) coefficients and CSS(Common Sub-expression Sharing) technique for the filter implementation, efficient structure for multiplication block can be obtained. Function simulation for proposed structure is done by using the preamble with timing offset. Through Verilog-HDL coding and synthesis, it is shown that the proposed symbol timing offset synchronization structure can be implemented with low-area semiconductor.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.167-171
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• 2004

This study investigated a HSP70 expression of Puerariae Radix in cerebral ischemia. The global cerebral ischemia was induced by bilateral common carotid arteries occlusion under hypotension (40 mmHg) in Sprague-Dawley rats. After the treatment of Puerariae Radix extract, the heat shock protein 70 (HSP70) expressions were measured immunohistochemically. The upregulation of HSP70 expression in hippocampal regions resulted by cerebral ischemia. Then Puerariae Radix treatment demonstrated significant decrease of HSP70 expressions in CA1 region and dentate gyrus of the hippocampus as compared with control group. These results suggested that Puerariae Radix reveals the neuroprotective effect through the control of noxious stress stimulations to neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.405-413
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• 2022

Hair loss is a common status found among people of all ages. Since the role of hair is much more related to culture and individual identity, hair loss can have a great influence on well-being and quality of life. It is a disorder that is observed in only scalp patients with androgenetic alopecia (AGA) or alopecia areata caused by stress or immune response abnormalities. Food and Drug Administration (FDA)-approved therapeutic medicines such as finasteride, and minoxidil improve hair loss temporarily, but when they stop, they have a limitation in that hair loss occurs again. As an alternative strategy for improving hair growth, many studies reported that there is a relationship between the expression levels of prostaglandins (PGs) and hair growth. Four major PGs such as prostaglandin D2 (PGD2₂), prostaglandin I2 (PGI₂), prostaglandin E2 (PGE₂), and prostaglandin F2 alpha (PGF_2α) are spatiotemporally expressed in hair follicles and are implicated in hair loss. This review investigated the physiological roles and pharmacological interventions of the PGs in the pathogenesis of hair loss and provided these novel insights for clinical therapeutics for patients suffering from alopecia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.321-327
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• 2008

This study evaluated neuroprotective effects of Yanggyuksanhwa-tang (YST) on global cerebral ischemia of diabetic rats. On primary experiment, diabetic condition in rats was induced by streptozotocin injection. Secondarily, global cerebral ischemia was induced by bilateral occlusion of the common carotid artery with hypotension (BCAO) under the diabetic condition. Then neuroprotective effect of YST was observed with changes of neuronal c-Fos and Bax expressions, and GFAP expression in the brain tissues by using immunohistochemistry. YST treatment was resulted significant decrease of c-Fos expression in CA1 hippocampus induced by BCAO on diabetic rats. YST treatment was resulted significant decrease of Bax expression in CA1 hippocampus induced by BCAO on diabetic rats. YST treatment was resulted significant decrease of c-Fos expression in cerebral cortex and caudoputamen induced by BCAO on diabetic rats. YST treatment was resulted significant decrease of GFAP expression in cerebral cortex induced by BCAO on diabetic rats. These results suggest that YST has effects on neuroprotection against cerebral ischemic damage under diabetic condition. And it is supposed that neuroprotective effect of YST reveals by anti-apoptosis mechanism.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.165-170
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• 2020

In this paper, it was confirmed that scopoletin inhibits neuroinflammation induced by amyloid beta oligomer (Aβ_1-42) in microglial BV-2. The mechanisms of inflammatory cytokines and inflammatory mediators by scopoletin were identified. Alzheimer's disease is the most common neurodegenerative disease, but it is a disease whose specific etiology is unknown, and many studies are trying to solve it. We first measured the cell viability with the CCK-8 assay method to confirm that scopoletin and Aβ_1-42 are toxic to BV-2 cells. Expression levels of interleukin 1 beta (IL-1β), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nuclear factor-κB (NF-κB) in inflammatory reactions induced by Aβ_1-42 with western blot were analyzed. The ANOVA assay was used to compare protein expression differences between BV-2 cells treated with Aβ_1-42 alone and BV-2 cells pretreated with Aβ_1-42 and scopoletin. Therefore, this study suggested that scopoletin is worth developing as a neuroinflammatory protection agent for Alzheimer's disease in the future.

• Coupled systems mechanics
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• v.4 no.3
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• pp.263-277
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• 2015

This paper presents a coupled FEM-BEM strategy for the numerical analysis of elastodynamic problems where infinite-domain models and complex heterogeneous media are involved, rendering a configuration in which neither the Finite Element Method (FEM) nor the Boundary Element Method (BEM) is most appropriate for the numerical analysis. In this case, the coupling of these methodologies is recommended, allowing exploring their respective advantages. Here, frequency domain analyses are focused and an iterative FEM-BEM coupling technique is considered. In this iterative coupling, each sub-domain of the model is solved separately, and the variables at the common interfaces are iteratively updated, until convergence is achieved. A relaxation parameter is introduced into the coupling algorithm and an expression for its optimal value is deduced. The iterative FEM-BEM coupling technique allows independent discretizations to be efficiently employed for both finite and boundary element methods, without any requirement of matching nodes at the common interfaces. In addition, it leads to smaller and better-conditioned systems of equations (different solvers, suitable for each sub-domain, may be employed), which do not need to be treated (inverted, triangularized etc.) at each iterative step, providing an accurate and efficient methodology.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.2
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• pp.192-197
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• 2017

In this paper, image filter optimization method based on common sub-expression elimination is proposed for low-power image feature extraction hardware design. Low power and high performance object recognition hardware is essential for industrial robot which is used for factory automation. However, low area Gaussian gradient filter hardware design is required for object recognition hardware. For the hardware complexity reduction, we adopt the symmetric characteristic of the filter coefficients using the transposed form FIR filter hardware architecture. The proposed hardware architecture can be implemented without degradation of the edge detection data quality since the proposed hardware is implemented with original Gaussian gradient filtering algorithm. The expremental result shows the 50% of multiplier savings compared with previous work.