• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.701-713
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• 2009

This paper studies a method for reducing performance degradation due to losing sub-carrier orthogonality caused by power transient between physical channels in LTE uplink transmission. The pattern of inter-carrier interference(ICI) caused by power transient is different from what has been studied for doppler shift, in that its pattern occurs at front and rear sides of channels in each period of power transient. The reason of ICI's occurrence results from power difference between channels, power transient duration, multi-path channel delay spread, and numbers of sub-carrier. New criterion is proposed to find out number of taps of multi-tap equalizer enough to improve the ICI. The scheme is to determine the number of taps of multi-tap equalizer when a normalized interference or a normalized ICI is greater than a normalized noise. Simulation results show that the number of taps is flexibly adjusted according to SNR(Signal to Noise Ratio) of a received signal to improve Bit Error Rate(BER), while the complexity of the proposed scheme is reduced down to 88 percentage of the classical method.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.105-112
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• 1994

To investigate the migration behavior of contaminants in rocks. adsorption and diffusion experiments for Sr as a sorbing contaminant and for Cr-EDTA as a non-sorbing contaminant were carried out on granitic rocks. The Sr adsorption on separated minerals and crushed rocks tends to slightly increase with increasing pH. It also greatly decreases with the increase of ionic strength in NaCl solution. Among separated minerals, biotite and sericite have adsorbed much more amount of Sr than other rock-forming minerals, such as quartz, plagioclase, and potassic feldspar, because the specific surfaces and cation exchange capacities of phyllosilicates are generally much greater than those of the other rock-forming minerals. The intrinsic diffusion coefficients of Cr-EBTA for granitic rocks differ little from those of Sr. This indicates that they are independent of water-rock interactions. Experimental data show that the intrinsic diffusion coefficients are positively correlated with the porosities of the rocks. They are close to the theoretically predicted values, especially in pre-steady state diffusion region, with the increase of rock sample thickness.

• Tunnel and Underground Space
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• v.26 no.5
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• pp.348-362
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• 2016

This study describes the results of blasting overbreak analysis using the stereo photogrammetry method in an underground mine. For comparing its quantitative measurements, LIDAR system was applied to the test site and blasting overbreak was analyzed for 4 test blasting operations. The difference in values obtained from the two methods showed only 0.81% in volume and 1.05% in area, respectively, therefore authors verify the field applicability of stereo photogrammetry method on underground mine. The volumes of overbreak measured from 4 test blastings were $29.84m^3$, $22.45m^3$, $14.54m^3$ and $5.46m^3$, respectively, in photogrammetry analysis on excavation surface, and it was shown that the volume of overbreak decreases with blasting sequence. From these measurements, it is concluded that the stereo photogrammetry method can describe the underground excavation surface effectively and the its quantitative data can be used for analysis of volume, area and overbreak of excavation zone.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.597-602
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• 2021

Even in the era of the 4th industrial revolution, the prevention of industrial accidents is still an important issue in industrial sites. In solving the problem of industrial safety, a product can be difficult to market if there is a lack of standard or method for a reliable performance evaluation. The purpose of this study was to develop and evaluate a test method for a wearable airbag product for protecting the body from falls that was newly developed to respond to fall accidents in industrial sites. As a research method, reliable evaluation standards were developed and applied through four stages of the evaluation and development process (Step 1: Product review, Step 2: Data research, Step 3: Expert meeting, Step 4: Drawing evaluation standard). In addition, the impact force was evaluated according to the developed evaluation standard. The fall impact force obtained through the evaluation showed a reduction effect of approximately 96% compared to the existing impact force. Therefore, the fall impact force was reduced significantly when the airbag was applied. This will enable new convergence products to be launched on the market and produce an environment where industrial workers can work safely.

• Asia Marketing Journal
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• v.13 no.3
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• pp.249-264
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• 2011

Brand is the major enduring asset of a company and more valuable than the totality of specific products and facilities. Thus brands are powerful assets that must be carefully developed and managed. The company should design and implement marketing activities and marketing communication programs to build and grow the brand value. Strarbucks, Samsung Galaxy, and Nike brands get a price premium and generate strong customer loyalty. A power brand has high brand equity, which is the differential effect that brand knowledge has on consumer response to the marketing of that brand. Brand equity is created when brands have strong, favorable and unique brand associations with customers and high level of brand awareness. Therefore marketers in building a strong brand should ensure to develop the right type of customer experiences with products and effective integrated marketing communication(IMC) programs to create the brand equity. Since 2007 Sinhan card acquiring the LG card has developed the new brand identity and carefully managed the advertising campaign and other marketing communication mix tools to create the high brand awareness and differential brand image. In this case study we examine how Sinhan card with the goal of being No.1 brand in the credit card market has developed and implemented the IMC Strategy to build a high level of consumer brand awareness, unique brand image and strong customer relationship.

• KDI Journal of Economic Policy
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• v.34 no.3
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• pp.31-65
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• 2012

We study the sustainability of the current fiscal policy of Korea, and the effects of the social welfare policy expansion, which has been recently discussed among the political circles, on the government budget and the generational equity, using generational accounting. We follow the generational accounting approach, considering the fact that most of the social welfare policies are the entitlement programs, which imposes the limitation of the policy maker's discretion to control the cost of their provision. The social welfare expenditure will change due to the change in the policy environments of the future, such as population aging. Therefore, we need to take into account the government cash flow of the future as well as of the present to investigate its effects on the fiscal sustainability, which implies that the national debt or the budget balance is not a proper index for the investigation. Our findings are as follows. The current fiscal policies are not sustainable, and the long-term budgetary imbalance is shown very serious. The required tax adjustment, which is defined as the percentage change of tax burden required to attain the long-term budgetary balance, is very large. Unless the level of the government expenditure is properly controlled, the tax burden and the social contribution level will rise to the untolerable level. Moreover, the expansion of the social welfare policies, which has been discussed among the political circles, will substantially increase the fiscal burden of the future generations. Even though the provision of the free lunch to the primary and the secondary school students, the free child care, and the discounted college tuition do not increase the fiscal burden much, because their magnitude at present is not large and will decrease due to the decrease in the number of the newborns and the students resulting from the fall in the fertility rate, that of the free health care service will increase tax burden of the future generations very much, because the magnitude of the government expenditure needed at present is very large and the population aging will further increase the magnitude of the health care expenditure. The findings indicate that the structural reforms, to prevent the explosive increase in the social welfare expenditure in the future, are necessary before the implementation of the welfare policy expansion. In particular, the cost control of the social transfers to the elderly needs to be made, because the speed of the population aging of Korea is among the highest in the world. The findings also indicate that the budget balance or the national debt can cause the fiscal illusion, which makes the Korean government budget look sound, even though the fiscal policy will rapidly increase the social welfare expenditure in the future, as the population ages. The generational accounting, which takes into account the cash flow of the future as well as of the present, unlike the budgetary balance and the national debt, which shows the results of the government financial activities of the past and the present, is a useful method to overcome the fiscal illusion.