• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.103-111
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• 2003

This study proposes methodology deterimining a basic pedestrian crossing capacity that plays a critical role in the installation of pedestrian signal at the crosswalks. The methodology is based on the pattern of vehicle arrived at the crosswalks. Erlang distribuion is used as headway distribution that can cover the various levels of flow rate. Models using Erlang distribution are represented by Erlang parameter (K) of 1, 2, or 3 at 2-, 4-, or 6-lane roadway in both directions. In addition, this study considered the only type of road with a pedestrian refuge area in the median that is used to wait for the allowable gap provided by the flow of another direction. As a result, the pedestrian capacity decreases as flow rate increases and Erlang parameter increases for the road with the pedestrian refuge. This study develops the models to determine the pedestrian capacity under a variety of flow rates and the outcomes of this study could be used as the criteria for the determination of the installation of pedestrian signal or for the provision of pedestrian refuge in the median of road.

• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.353-360
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• 2017

Background: A critical features of Alzheimer's disease (AD) is cognitive dysfunction, which partly arises from decreased in acetylcholine levels. AD afftected brains are characterized by extensive oxidative stress, which is thought to be primarily induced by the amyloid beta ($A{\beta}$) peptide. In a previous study, Cinnamomum loureiroi tincture inhibited acetylcholinesterase (AchE) activity. That study identified AChE inhibitor in the C. loureiroi extract. Furthermore, the C. loureiroi extract enhanced memory in a trimethyltin (TMT)-induced model of cognitive dysfunction, as assessed via two behavioral tests. Rosa laevigata extract protected against oxidative stress-induced cytotoxicity. Administrating R. laevigata extracts to mice significantly reversed $A{\beta}$-induced learning and memory impairment, as shown in behavioral tests. Methods and Results: We conducted behavioral to examine the synergistic effects of C. loureiroi and R. laevigata extracts in inhibiting AChE and counteracting TMT-induced learning and memory losses. We also performed biochemical assays. The biochemical results showed a relationship between increased oxidative stress and cholinergic neurons damage in TMT-treated mice. Conclusions: A diet containing C. loureiroi and R. laevigata extracts ameliorated learning and memory impairments in the Y-maze and passive avoidance tests, and exerted synergistic inhibitory effect against AChE and lipid peroxidation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.2
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• pp.113-126
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• 2009

In the recent years, health effect of dimethylformamide(DMF) has been one of critical industrial hygiene issues. There might be many factors to increase the exposure level of DMF. Among those factors, industrial ventilation would be one of the main factors. In this study, industrial ventilation systems of printing processes in synthetic leather factories were thoroughly surveyed and the improved ventilation systems were proposed. 7 synthetic leather factories were selected for this study. After the ventilation systems were visually inspected, each component of the system was tested by using the appropriate instruments. Hood face velocities, fan exhaust flow rates, fan static pressures, fan rotation rates, etc were measured. In addition, flow visualization techniques were used to observe flow patten around hoods and inside the factory buildings. After gathering all qualitative and quantitative information, the test results were analysed to see if any improvement might be necessary. For the system to be improved, the re-design plans were made by using computational fluid dynamics softwares. The softwares used in this study were AIRPAK and STAR-CD. The effectiveness of the several improvement options were tested, then the best cost effective option was selected. Finally, the standard ventilation systems were proposed to minimize the exposure levels of DMF.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.3
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• pp.150-156
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• 2016

Extract of Broussometia kazinoki Rhizodermatis has been traditionally used for geopoong, diuresis, hwalhyeol. In the present study, the apoptotic effect of methanol extract of Broussometia kazinoki (MBK) were investigated. Cell viability of A549 cells was measured by MTT assay. Apoptosis-related protein and MAPK protein levels were measured by Western blot. Chromatin condensation of A549 cells was stained with DAPI. MBK inhibited cell proliferation of A549 cell. Based on DAPI staining, MBK-treated cells manifested nuclear shrinkage, condensation and fragmentation. Treatment of A549 cells with MBK resulted in activation of the caspase-3, -8, -9 and cleavage of poly ADP-ribose polymerase (PARP). In the upstream, MBK increased the expressions Bax and Bak, decreased the expression of Bcl-2, and augmented the Bax/Bcl-2 ratio. MBK-induced apoptosis was accompanied by sustained phosphorylation of JNK, p38 MAPK and apoptosis signal-regulating kinase (ASK)-1. These results suggest that MBK induced apoptosis in A549 cells through Bcl-2 family protein-mediated mitochondria/caspase-3 dependent pathway. In addition, MBK increased the activation of ASK-1, which are critical upsteam signals for JNK/p38 MAPK activation in A549 cancer cells.

• Molecules and Cells
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• v.40 no.2
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• pp.151-161
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• 2017

Proper synaptic function in neural circuits requires precise pairings between correct pre- and post-synaptic partners. Errors in this process may underlie development of neuropsychiatric disorders, such as autism spectrum disorder (ASD). Development of ASD can be influenced by genetic factors, including copy number variations (CNVs). In this study, we focused on a CNV occurring at the 16p11.2 locus in the human genome and investigated potential defects in synaptic connectivity caused by reduced activities of genes located in this region at Drosophila larval neuromuscular junctions, a well-established model synapse with stereotypic synaptic structures. A mutation of rolled, a Drosophila homolog of human mitogen-activated protein kinase 3 (MAPK3) at the 16p11.2 locus, caused ectopic innervation of axonal branches and their abnormal defasciculation. The specificity of these phenotypes was confirmed by expression of wild-type rolled in the mutant background. Albeit to a lesser extent, we also observed ectopic innervation patterns in mutants defective in Cdk2, Gq, and Gp93, all of which were expected to interact with Rolled MAPK3. A further genetic analysis in double heterozygous combinations revealed a synergistic interaction between rolled and Gp93. In addition, results from RT-qPCR analyses indicated consistently reduced rolled mRNA levels in Cdk2, Gq, and Gp93 mutants. Taken together, these data suggest a central role of MAPK3 in regulating the precise targeting of presynaptic axons to proper postsynaptic targets, a critical step that may be altered significantly in ASD.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.2
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• pp.110-115
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• 2010

This study was conducted to estimate the feasibility using thermal image measurement that is applicable to internal leak diagnosis for the power plant valve. Abnormal heating of valve surface associated with high temperature steam f10w toward valve outlet side in the condition of low temperature is a primary indicator of leakage problems in high temperature and pressure valves. Thermal imaging enables to see the invisible thermal radiation that may portend impending damage before their condition becomes critical. When steam flow in valve outlet side in the condition of low temperature is converted into heat transmitted through the valve body due to the internal leakage in valve. The existence of abnormally increasable leakage rate in the valve will result in abnormally high levels of heat to be generated that can be quickly identified with a thermal image avoiding energy loss or damage of valve component. From the experimental results, it was suggested that the thermal image measurement could be an effective way to precisely diagnose and evaluate internal leak situation of valve.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.855-864
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• 2004

Programmers can be got the test-related information for implementation without interference of source code complexity by use of the formal specification. Especially the external inputs and system responses can be represented precisely by formal specification in testing phase of web-based software systems. This paper suggests a method of extracting test cases by use of formal specification. Object-Z formal specification represents various test-related information for complex functions of web-based applications. State Transition Models could be built from the formal specification so that test scenarios were extracted from STDs from the highest level to detail levels. The target system for verification of this method is a web-based banking system which is necessary to be secured and critical on errors. This method would be an important factor in automatizing test procedure for web-based application software systems combining the user-base test technique.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.487-500
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• 2020

Stiffeners can be utilised to enhance the strength of thin-walled wind turbine towers in engineering practise, thus, structural performance of wind turbine towers by means of different stiffening schemes should be compared to explore the optimal structural enhancement method. In this paper two alternative stiffening methods, employing horizontal or vertical stiffeners, for steel tubular wind turbine towers have been studied. In particular, two groups of three wind turbine towers of 50m, 150m and 250m in height, stiffened by horizontal rings and vertical strips respectively, were analysed by using FEM software of ABAQUS. For each height level tower, the mass of the stiffening rings is equal to that of vertical stiffeners each other. The maximum von Mises stresses and horizontal sways of these towers with vertical stiffeners is compared with the corresponding ring-stiffened towers. A linear buckling analysis is conducted to study the buckling modes and critical buckling loads of the three height levels of tower. The buckling modes and eigenvalues of the 50m, 150m and 250m vertically stiffened towers were also compared with those of the horizontally stiffened towers. The numbers and central angles of the vertical stiffeners are considered as design variables to study the effect of vertical stiffeners on the structural performance of wind turbine towers. Following an extensive parametric study, these strengthening techniques were compared with each other and it is obtained that the use of vertical stiffeners is a more efficient approach to enhance the stability and strength of intermediate and high towers than the use of horizontal rings.

• Experimental and Molecular Medicine
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• v.51 no.2
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• pp.9.1-9.10
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• 2019

Mesangial cell proliferation has been identified as a major factor contributing to glomerulosclerosis, which is a typical symptom of diabetic nephropathy (DN). Lysophosphatidic acid (LPA) levels are increased in the glomerulus of the kidney in diabetic mice. LPA is a critical regulator that induces mesangial cell proliferation; however, its effect and molecular mechanisms remain unknown. The proportion of ${\alpha}-SMA^+/PCNA^+$ cells was increased in the kidney cortex of db/db mice compared with control mice. Treatment with LPA concomitantly increased the proliferation of mouse mesangial cells (SV40 MES13) and the expression of cyclin D1 and CDK4. On the other hand, the expression of $p27^{Kip1}$ was decreased. The expression of $Kr{\ddot{u}}ppel$-like factor 5 (KLF5) was upregulated in the kidney cortex of db/db mice and LPA-treated SV40 MES13 cells. RNAi-mediated silencing of KLF5 reversed these effects and inhibited the proliferation of LPA-treated cells. Mitogen-activated protein kinases (MAPKs) were activated, and the expression of early growth response 1 (Egr1) was subsequently increased in LPA-treated SV40 MES13 cells and the kidney cortex of db/db mice. Moreover, LPA significantly increased the activity of the Ras-related C3 botulinum toxin substrate (Rac1) GTPase in SV40 MES13 cells, and the dominant-negative form of Rac1 partially inhibited the phosphorylation of p38 and upregulation of Egr1 and KLF5 induced by LPA. LPA-induced hyperproliferation was attenuated by the inhibition of Rac1 activity. Based on these results, the Rac1/MAPK/KLF5 signaling pathway was one of the mechanisms by which LPA induced mesangial cell proliferation in DN models.

• Cross-Cultural Studies
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• v.29
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• pp.315-339
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• 2012

The Chilean educative policies as the Voucher System and the privatization have been almost same from the Pinochet government and the ones of "Concertacion" or "Democratic Alliances" until now. Because the neoliberal regime has dominated principally in Chile the area of the education. In this study first of all I will analyze the procedures of the violent repression of the leftist politicians and the intellectuals of the universities by the Pinochet government. And the importance of the reform of the law of education in 1980 was emphasized and the other one in 1990 one day before the retirement of Pinochet. We can comprehend the fact that the education would have been used as a tool to achieve the development of the country and the economic one sacrificing the public and equalitarian values of the education. And the competence, the efficiency and the quality of the education have been emphasized through the policies as example the rights of the selection of the schools by the parents as like a product in the market. But the result was the enormorors expansion of the private education not only in the secondary schools but also in the universities. And also has been intensified "the segregation and the discrimination" of the students jerarquitized by the different social-economic levels of the parents. The Chilean people including the middle class did not realize rightly the inherent problems of the neoliberal regime having the equivocation as if the private schools should have been better than the public ones. However the high level of the public university education became to be dominated by the acomodated class. This was the cause of the last year's great scale of the demonstration of the Chilean students. The most important thing is that these matters was agravated not by the Pinochet government but by the ones of "Concertacion" or "Democratic Alliances". Because these governments tried to maintain the neoliberal regime by means of the education only arranging the small problems or contratiempos.