• Fire Science and Engineering
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• v.27 no.1
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• pp.46-51
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• 2013

In this study a lab scale seismic test method which is able to evaluate seismic resistant performance of the fire protecting components in case of earthquake was developed. This seismic test consists of equivalent accelerating and temporary accelerating. The former is to search for resonance frequency and the latter is to simulate vibrating by earthquake with intensive magnitude. The frequency and displacement accelerated to the components was decided by maximum acceleration of gravity, and whether or not they could maintain function was tried to be confirmed. This test method is expected as an effective one for evaluating seismic resistant performance for the fire protecting components.

• Journal of the Korea Computer Graphics Society
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• v.17 no.2
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• pp.37-43
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• 2011

OpenVG and SVG Tiny are the most widely used 2D vector graphics technologies for outputs in the various embedded environments including smart phones. Especially, to show high refresh rates on the high resolution screens, it is necessary to effectively accelerate them. Until now, OpenVG and SVG Tiny are available as hardware implementations such as the fully-dedicated graphics chips or full software implementations. Currently available vector graphics silicon chips are relatively expensive and require high power consumption. In contrast, previous full software implementations show lower performance even with almost 100% CPU usages, which would disrupt other multi-threaded applications, In this paper, we present a cost-effective way of accelerating both of OpenVG and SVG Tiny, based on the multimedia-processing hardware, which is wide-spread on the media devices and mobile phones. Through the effective use of these multimedia processors, we successfully accelerated OpenVG and SVG Tiny at least 3.5 times to at most 30 times, even with lower power consumption and lower CPU usage.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.2
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• pp.67-75
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• 1982

A study on the effect of water reducing agent on the various characteristics of concrete has been conducted. The experimental results of the study are summarized as follows. 1. Slump test for the concrete added water reducing setretarding agent in proper quantity have been conducted. According to the test results, the decreasing rate of slump value become bigger than plain concrete with increase of the unit weight of cement and elapse of time 2. In case the proper quantity content of maximum compressive strength in Fig. 5 of water reducing set retarding agent is added, unit weight of water is decreased about 15% or so as compared with plain concrete. with the increase of water reducing set accelerating agent content unit weight of water is decreased much more, And other hand, amount of air entraining shows the increasing tendency with the increase of water reducing agent content. 3. The adding rate of water reducing agent which produce maximum strength shows that WR-CH and WR-SA which is water reducing set-starding agent is 0.2% and WR-CO is 0.5% and that WS-PO which is water reducing set accelerating agent is 0.5 4. compressive strength jof the concrete made of sulfate resistant cement shows less than the strength of normal portland cement at initial strength but the strength of both cement shows almost same at curing age of 28 days. 5. when proper quantity of water reducing set retarding agent is used, boned strength is increased about 15% at curing age of 28days. 6. According to the result of durability test, dynamic young's mudulus of elasticity at plain concrete is decreased about 50% as compared with initial step at 300 cycle of freezing and thawing after curing age of days. on the contarary the concrete used water reducing agent is decreased less than 7%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.247-251
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• 1999

In spite of various bio-functionalities of chitosan, the effects in vivo were still ambiguous because of its low absorption on organism. Therefore, chitosan oligosaccharides (COSs) are necessary to elucidate for an efficient utilization in vivo. COSs were prepared from chitosan using ultrafiltration membrane enzymatic reactor system with MWCO (molecular weight cut-off) 3,000 Da of membrane. Calcium absorption accelerating effect using COSs was examined by two methods, in vitro and in vivo. In vitro experiment, calcium absorption by the addition of COSs in a mixture solution of calcium and phosphate was higher approximately $50\%$ than that by control. In vivo using rats, group taken the diet contained $1\%$ COSs anil calcium chloride decreased about $75\%$ of calcium content excreted from feces, and then, showed about $15\%$ increase in breaking force of femur. These results demonstrated that COSs definitely involved in calcium metabolism in vivo.

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.239-244
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• 2009

This paper aims to report the effect of surface treatment on graphite and its effect on the improvement of $Al_2O_3$ and $nano-Li_4Ti_5O_{12}$. The structure and property of surface treatment on graphite were determined by scanning electron microscopy, transmission electron microscopy and electrochemical property and safety were determined by charge/discharge cycler, accelerating rate calorimeter. The composite with different metallic oxide exhibited the first efficiency of 82.5% and specific capacity of 350 mAh/g. Although the composite showed same efficiency and specific capacity at first cycle, surface treatment on graphite by $nano-Li_4Ti_5O_{12}$ exhibited a higher charge/discharge rate, cycle life and thermal stability.

• Strategy21
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• s.43
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• pp.125-174
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• 2018

The purpose of this paper is to analyze the status of naval arms race in Northeast Asia. To this end, the scope of the research was limited to national security strategies, maritime strategies and naval strengthening of the United States, China, Russia and Japan. The major powers' active maritime strategies and naval arms race give some strategic implications to the Republic of Korea Navy as follows. First, China and Japan, unlike the past, are actively using submarines in offshore waters including the Korean Peninsula. Therefore, the ROK Navy must successfully promote the Jangbogo-III-class submarine, which is currently constructed, and get a nuclear-powered submarine and P-8 MPA capable of long-range and long-time operations to enhance ASW capability. Second, North Korea's current building submarines capable of loading SLBMs and SLBMs are a new threat to the ROK Navy. The current building KAMD, which focuses on terminal phase defense, cannot effectively respond to North Korea's SLBMs and should be converted to a multi-layered defense system including SM-3 at a mid-course phase. Third, as China militarizes the South China Sea, the instability of the South China Sea is growing. Therefore, the ROK Navy should strengthen its maritime cooperation with the regional countries such as Japan and ASEAN navies to protect SLOC. In conclusion, the ROK Navy needs to build a strong naval power to keep in mind that the 21st century naval rivalry in Northeast Asia is accelerating. The navy must do one's best to protect national strategic and vital interests by strengthening cooperation with regional countries. South Korea is also accelerating its defense reforms in accordance with the pattern of future warfare and the ROK Navy do one's best to have a balanced naval capability capable of actively operating in the offshore waters.

• Journal of Welding and Joining
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• v.15 no.3
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• pp.88-98
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• 1997

Welding defects, such as porosity and spike, have sometimes occurred in deep penetration electron beam welds. These defects are known to be one of the serious problem in electron beam welds. So, effects of active parameters ($a_b$) on bead shape and occurrence of defects in electron beam welds of heavy section 9%Ni steel plates were investigated. Partial penetration welding in flat position, and deep penetration welding of 10 ~ 28mm depth were investigated in this study. It is desirable to select low accelerating voltage and above the surface focus position $a_b$$\geq$1.2 at which a wine-cup shaped bead is obtained to avoid the welding defects such as spike and root porosity. When the accelerating voltage of electron beam was low (90kV), active parameter ($a_b$) did not influence on the bead width, penetration depth and weld defects significantly. However, in case of high voltage ($\geq$120kV), active parameter ($a_b$) was sensitively associated with penetraton depth and weld defects, i.e. when the active parameter (($a_b$) was in the range of 0.6 to 1.0, the depth of penetration was always over the target (23mm), while the depth of penetration was dramatically decreased with further increase of active parameter ($a_b$). The weld defects were decreased with the increase of active parameter $a_b$ resulting in the decrease of energy density of the focused beam in the root part of fusion zone.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.7-14
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• 2003

This study has investigated the feasibility of caissons for accelerating consolidation (C.A.C.) constructed in clays with anisotropic permeability by improving the former study on C.A.C. in isotropic clays. Analytical solutions for excessive pore water pressures of two-dimensional consolidation equation and average degrees of consolidation with varying time factors have been provided by considering anisotropic permeability. With varying anisotropic permeability ratios of 5, 10, and 50, consolidation times required for reaching the average degree of consolidation of 90% for C.A.C. at the section of $\xi$=0.1 are shorter than those for conventional caissons by 8, 13, and 47 times, respectively. C.A.C. is more effective in reducing consolidation time as anisotropic permeability ratio increases. This study provides also plots for average degrees of consolidation versus the width to depth ratios of analyzed sections and permeability ratios, which will enable engineers to determine easily average consolidation settlements.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.348-358
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• 2016

This study reveals a change in the growth cycle of metropolitan with analyzing the population of Seoul metropolitan area and identifies the characteristics of each urban area. For this, the exponential growth of the city, Roxy index, which in recent years been actively studied in Japan, has applied. As a result, the entire metropolitan area and central areas, and the southern region are about to move to the accelerating centralization phase. In the phase of suburbanization are highly likely to turn into the new phase of regression phase. In addition, the northern and eastern suburbs are currently in progress with the accelerating decentralization phase and are expected to be converted in the decelerating decentralization phase. Through this implication in Seoul metropolitan area, it is necessary to carry out the policy responses about regional maintenance by connecting to the changes in direction and speed of cycle phase of city. The results of this study can be used as basic data to determine the long-term future growth and decline of the metropolitan area.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1193-1200
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• 2001

There are many regulation test methods to be related with engine emissions such as CVS-75, D-13, ECE-15 modes and so on. Most of these modes are consisted of lots of transient conditions that have rapid acceleration, deceleration and cranking modes. In this experimental research, the engine characteristics of cranking, accelerating and power output in a S.I. engine were studied to compare with neat gasoline and alternative fuels of M30 (methanol 30%, aromatic series 32%, non-aromatic 38%) and M50 (methanol 50%, aromatic 30%, non-aromatic 20%) for performance and exhaust emissions. The results show that reformulated methanol fuels are better emissions reduction of 15.7% over than that of neat gasoline fuel especially in HC and CO emissions at cranking mode. And the accelerating performances coincide with the results of distillation curve. CO concentration for M50 fuel is varied in a just little for the condition of slow acceleration. At wide-open throttle condition, brake specific energy consumption of reformulated fuels is increased and thermal efficiency is some what lower than that of gasoline fuel.