• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.254-260
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• 1997

Chloride-induced corrosion of reinforcement is one of the main factors which cause the deterioration of concrete structures. Durability and service lives of the concrete sturctures should be predicted in order to minimize the risk of corrosion of reinforcement. The objective of this study is to suggest the basis of analytical methods of predicting the corrosion threhold time of concrete structures. Based on the chemistry and physics of chloride ion transport and corrosion process, chloride intrusion with various exposure conditions, variability of diffusivity and transport of pore water in concrete are taken into consideration in applying finite element formulation to the predicion of corrosion threhold time. The effects of main factors on the prediction of chloride intrusion and corrosion threhold time are examined. In addition, after chloride diffusivities of several mixture proportions with different parameters are measured by chloride diffusion test, the exemplary anayses of corrosion threhold time of those mixture proportions are carried out.

• Environmental Analysis Health and Toxicology
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• v.17 no.4
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• pp.315-324
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• 2002

Risk communication can be defined as the exchange of information about the nature, magnitude, significance, acceptability, and management of risk. The effect of risk communication on the perception and knowledge towards risk of environmental pollutants and it's related factors were investigated in this study. To investigate perception and knowledge of students and teachers towards risk of environmental pollutants, we conducted the survey using self-administrated questionnaire. The subjects were 574 for the first survey and 465 for the seconds survey from May to June, 2000. The main methods of transmission used in this study- through video tape, visual materials, question and answer, and participation in measuring pollutants - were not a one - way street. But an interactive process where information and opinions were exchanged among individuals, groups, and institutions. Environmental pollutants measured with participation of study subjects was Radon in the class room. The concentration of Radon was measured using E -PERM Device by installing it at each site for about 5 days. Subjects showed much interest in environmental pollution. Also, more than 98％ of total subjects were perceived as Korea is seriously contaminated at present. By risk communication activity, risk perception of all subjects about Radon was increased, on the other hand, risk perception of Dioxin was decreased except for elementary student. Moreover, knowledge of all subjects about environmental risk was significantly increased (p =0.0001) and effort of reducing environmental pollution was more increased (p<0.05). There is need to further develop, refine, and integrate these approaches environmental risk communication study, there is an even more pressing need to accelerate the diffusion of environmental risk communication practice into government and organizations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.620-629
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• 2010

The analogue radio broadcasting was proven to be a successful and efficient media of delivering information because of free content and wide availability of cheap receivers. But the competition was more dropped than any other media due to the limited amount of radio spectrum that is available. The risk of doing nothing is to miss the opportunity and to loss existing audiences in the long term, or to be locked into inefficient proprietary systems. That is the reason why it is important to act now. It is time for regulators and market participants to hone their strategies, by clearly establishing factors to adopt the digital radio and to facilitate its diffusion. The purpose of this study is to find adoption factors that affected to potential users of digital radio broadcasting. Former research based on diffusion of innovation theory showed that adoption of innovation is affected by demographic variables, media usage and consumer's attitude of innovation. In this study based on a consumer survey, we examined those factors and characteristics of each steps that suggested in diffusion of innovation theory. The findings of this study have implications to explore the suitable technologies and services of digital radio broadcasting.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.69-101
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• 2008

We empirically investigate the option leverage property that should be priced under much more general conditions than the Black-Scholes assumptions and the option redundancy property that is based on the assumption that the underlying asset price follows a one-dimensional diffusion process and examine the systematic risk factors implied in the return dynamics of KOSPI 200 index options. We find that the option leverage pattern is similar to the theoretical result but the options are not redundant securities and in the nonlinear structure of option payoffs, the traders of KOSPI 200 index options price the systematic higher-moments and the negative volatility risk premium significantly affects delta-hedged gains, even after accounting for jump fears. But the empirical evidence on jump risk preference is less conclusive.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.858-861
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• 2000

This paper presents the characteristics of cutting fluid atomization due to its application method. In this study three different application methods; nozzle, jet, mist type is adopted for evaluating the cutting fluid's effect in terms of machinability and environmental consciousness. Cutting fluids are widely used to cool and lubricate the cutting zone in machining process. Cutting fluids mist via atomization in spin-off process can be affected to health risk. To satisfy the increasing concern of health and environment problem and keep the machinability or productivity it is necessary to establish the resonable strategy of cutting fluid usage and optimal control. Tool wear and cutting fluid diffusion rate in the air were measured as machinability index and environmental index in a few turing operation. Through this basic approach it can be also provide the optimization of cutting process and improvement of machine tool design in achieving environmentally conscious machining.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.356-362
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• 2023

The risk of climate change has been long acknowledged, and ongoing efforts to overcome this issue, within the shipping sector, with the international maritime organization playing a central role. Conducting research on characteristics of soot formation is crucial to control its occurrence within the combustion process. In this study, the laser extinction method and chemical reaction numerical analysis were employed to examine the alterations in the state of chemical species associated with flame temperature, flame visual, and soot formation by mixing nitrogen, an inert gas, in the counterflow diffusion flame based on ethylene gas. The findings of the study suggest that as the mixing ratio of nitrogen increased, both the flame temperature and soot volume fraction decreased. Additionally, the area in which soot particles were distributed also decreased, and the volume fraction decrease rate declined when the mixing ratio increased by more than 30%. The mole fraction of the chemical species involved in soot growth also decreased. the chemical species associated with the HACA reaction were affected by variations in the hydrocarbon fuel ratio, and the chemical species related to the odd carbon path were confirmed to be affected by the flame temperature as well as the hydrocarbon fuel ratio.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.73-94
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• 2003

In general, the interest rate is forecasted by the parametric method which assumes the interest rate follows a certain distribution. However the method has a shortcoming that forecasting ability would decline when the interest rate does not follow the assumed distribution for the stochastic behavior of interest rate. Therefore, the nonparametric method which assumes no particular distribution is regarded as a superior one. This paper compares the interest rate forecasting ability between the two method for the Monetary Stabilization Bond (MSB) market in Korea. The daily and weekly data of the MSB are used during the period of August 9th 1999 to February 7th 2003. In the parametric method, the drift term of the interest rate process shows the linearity while the diffusion term presents non-linear decline. Meanwhile in the nonparametric method, both drift and diffusion terms show the radical change with nonlinearity. The parametric and nonparametric methods present a significant difference in the market price of interest rate risk. This means in forecasting the interest rate and the market price of interest rate risk, the nonparametric method is more appropriate than the parametric method.

• Korean journal of communication and information
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• v.35
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• pp.181-210
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• 2006

This frame analysis attempts to shed light on the process by which the Korean press constructs crisis as social reality through a series of risk reporting on food safety. Based on the FSSI(Food Safety Sentiment Index) developed by KIHASA(Korea Institute for Health and Social Affairs), 11 cases of food safety reports from 1989 to 2005 were collected from the Korean Integrated News Database System(KINDS) and analyzed to yield the following salient features: risk diffusion frame; attribution of responsibility frame; conflict frame. It was observed that the press exhibited a tendency to approach the food safety incidents from a bi-polarized perspective, amplifying dichotomy between the victim and the perpetrator rather than treating them as scientific, or environmental hazards that require precise and synthesized information for resolution. This occupational habit of attributing status to agents of news was also found to contribute towards construction of crisis as social reality.

• 한국디지털정책학회:학술대회논문집
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• 2005.06a
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• pp.13-28
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• 2005

The purpose of this study is to explore conquest plans of the barrier and resistance in innovation management. This paper focuses to understand the model of innovation that reflects adoption process stages and identify the factors that drive the resistance of consumers. Whenever organizations try to plan and implement some kind of innovation in organizations, they confront resistance in many ways. By understanding innovation resistance, organizations can not only design better innovations but can develop strategies to reduce resistance. Thus they accelerate innovation. Understanding the factors that drive the innovation resistance has important implications for both theoretical development and managerial action. These results indicate that people resist innovation strongly when it betrays their value, needs and beliefs or when they felt the pressure on self-conviction and mental risk, loss, and lack of knowledge.

• Structural Engineering and Mechanics
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• v.37 no.5
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• pp.459-473
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• 2011

The study of the early age concrete properties is becoming more important, as the thermal effects and the shrinkage, even in the first hours, could generate cracks, increasing the permeability of the structure and being able to induce problems of durability and functionality in the same ones. The detailed study of the stresses development during the construction process can be decisive to keep low the cracking levels. In this work a computational model, based on the finite element method, was implemented to simulate the early age concrete behavior and, specially, the evaluation of the cracking risk. The finite element analysis encloses the computational modeling of the following phenomena: chemical, thermal, moisture diffusion and mechanical which occur at the first days after the concrete cast. The developed software results were compared with experimental values found in the literature, demonstrating an excellent approach for all the implemented analysis.