• Journal of Technology Innovation
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• v.5 no.1
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• pp.181-205
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• 1997

There has been considerable controversy over the impacts of the tax credit on R&D expenditures in many countries. Korea has adopted various kinds of tax credit system to stimulate private firm' R&D expenditures. Korean government, Recently, is trying to reform tax system to reduce tax credit programmes according to Uruguay Round agreement and in line with OECD policy standards. The purpose of this paper is to analyze the effectiveness of current tax credit system on technology innovation in Korea and derive some policy implications over tax reform. In this paper, firstly, I investigate the size of tax reduction effects from each program in theoretical models and simulate the actual rate of individual tax incentive to a unit of R&D expenditure. I find that theoretically the reserve fund for technology development program has given the largest tax reduction effects to private firms irrespective of the R&D incentive system reform. Tax credit on R&D expenditure also has been very effective instrument to firm's tax reduction. Secondly, I try to measure the effectiveness of tax credit through the estimation of effective margianl tax rate between with the system and without the system of credit on R&D expenditure during the tax credit reform periods. I find that the tax credit on R&D has lowered firm's investment cost since the system introduced. I also have strong results that there has been a positive relation between the fluctuation of firm's R&D expenditure and the change of effective marginal tax rate. I suggest that it is better to sustain the system of tax credit on R&D for a while to increase firm's R&D expenditure.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.95-102
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• 2003

To Prevent the damage of power system facilities by snow accretion on transmission lines, a prototype expert system has been developed. The system has the basic functions of forecasting snow accretion on transmission lines and making a list of all feasible and effective deicing countermeasures to assist power system operators. As estimating of snow accretion on power lines and making countermeasure plans are very difficult to solve analytically, knowledge engineering can be an effective method for this problem. The heuristics about the effect of weather conditions on the snow accretion process on power lines and power system operation for the deicing constitutes main nile base. Simulation results based on past snow accretion accident data show that the proposed system is very premising.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.763-770
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• 2017

A radome mounted on the front of an aircraft can cause refraction errors for various reasons that occur during maneuver in seeking and tracking a target. This refraction error means that the microwave seeker is detecting apparent target. An Interactive Multiple Model (IMM) algorithm is applied to estimate radome slope mounted on an aircraft in 3D space. However, even though the parameter of uncertain system model such as radome slope can be estimated, the estimated performance can not be guaranteed when it exceeds the range of the predicted value. In this paper, we propose a method to update the predicted value by using the radome slope as the mode parameter of the IMM algorithm, and confirm the radome slope estimation performance of the proposed method.

• International Journal of Safety
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• v.1 no.1
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• pp.36-42
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• 2002

This paper is aimed at predicting the life of rubber insulating gloves under normal operating stresses from relatively rapid test performed at higher stresses. Specimens of rubber insulating gloves are subject to multiple stress conditions, i.e. combined electrical and thermal stresses. Two modes of electrical stress, step voltage stress and constant voltage stress are used in specimen aging. There are two types of test for electrical stress in this experiment: the one is Breakdown Voltage (BDV) test under step voltage stress and thermal stress and the other is lifetime test under constant voltage stress and temperature stress. The ac breakdown voltage defined as the break-down point of insulation that leakage current excesses a limit value, l0mA in this experiment, is determined. Because the very high variability of aging data requires the application of statistical model, Weibull distribution is used to represent the failure times as the straight line on Weibull probability paper. Weibull parameters are deter-mined by three statistical methods i.e. maximum likelihood method, graphical method and least squares method, which employ SAS package, Weibull probability paper and FORTRAN, respectively. Two chosen models for predicting the life under simultaneous electrical and thermal stresses are inverse power model and exponential model. And the constants of life equation for multistress aging are calculated using numerical method, such as Gauss Jordan method etc.. The completion of life equation enables to estimate the life at normal stress based on the data collected from accelerated aging test. Also the comparison of the calculated lifetimes between the inverse power model and the exponential model is carried out. And the lifetimes calculated by three statistical methods with lower voltage than test voltage are compared. The results obtained from the suggested experimental method are presented and discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1479-1485
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• 2012

The development of a technique for the real-time sensing of a curve section is very important for active rolling-stocks in order to improve the curving performance. However, conventional methods using expensive track inspection equipment or various complex sensors are not practicable to be applied to commercial vehicles. Therefore, we have proposed a new method to estimate the curve radius of a curve section. This method uses the relative displacements occurring between the body and the bogie when the rolling-stock is running on a curve. To verify the validity of this method, we conducted a vehicle dynamics simulation and test using a real vehicle on a test line. The results confirmed the validity of the proposed method. We expect that this method will be effectively applied in studies of active rolling-stocks to increase the curving performance using active control technology.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.75-81
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• 2008

The water shortage in mega cities in Asia, which face a rapid growth in urban population, is an outstanding problem. It is important, therefore, to accurately estimate the water balance in each city in order to use the limited water resources effectively. In this study, we estimated the potential water resources in し sixteen mega cities in Asia. The target cities were Delhi and Calcutta, India; Colombo, Sri Lanka; Dhaka, Bangladesh; Yangon, Myanmar; Bangkok, Thailand; Kuala Lumpur, Malaysia; Singapore; Jakarta, Indonesia; Hanoi, Vietnam; Beijing and Hong Kong, the People's Republic of China; Seoul, the People's Republic of Korea; Manila, the Philippines, and Sapporo and Tokyo, Japan. The potential water resources were estimated by subtracting the actual evaporation from the amount of rainfall. The actual evaporation was estimated using the potential evaporation obtained by Hamon's equation which requires the air temperature and the possible hours of sunshine. When the results of Hamon's and Penman's evaporation equations were compared, a considerable error appeared in the low latitude region. The estimation using Hamon's equation was corrected with the linear regression line of Hamon's and Penman's equations. A classification of the land cover was carried out based on satellite photographs of the target cities, and the volume of surface runoff for each city was obtained using the runoff ratios which depended on the land cover. As a result, the potential water resources in the above mega cities in Asia were found to be greater than the world average. However, the actual water resources which are available for one person to use are probably very limited.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.52-58
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• 2017

One of the most important elements of the management of chemical accident is threat zone estimation of fires, explosions and toxic gas dispersion based on chemical releases. The threat zone estimation is going to be standard of emergency response for the first defender and base line data of off-site risk assesment (hereinafter referred to as "ORA") and risk management plan (hereinafter referred to as "RMP"). Generally, ALOHA form EPA(U.S.) and Kora(from KOREA MINISTRY OF ENVIRONMENT) has been used for the off-site consequence analysis in Korea. However it is hard to predict accurate consequences rapidly in case of emergency. Hydrochloric acid is a multipurpose raw material used in many industrial applications such as chemical, metal and food industries. It is usually treated in concentrations from 10 ~ 35 %, and release accident have occurred frequently. In this study, we have developed a simplified estimating method and equation to calculate threat zone easily in case of emergency due to release accident of hydrochloric acid.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.4
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• pp.292-299
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• 2012

The line-of-sight(LOS) rate is estimated using Kalman filter in Radio-Frequency(RF) seeker. For the two axis gimbaled seeker, proper system modeling is considered and the basic filter structure is set up. The main issue for Kalman filter is choosing the proper process and measurement noise. For the measurement process, the signal to noise ratio(SNR) and other components are introduced. To cope with the eclipse problem or other abnormal seeker status, the pseudo input signal concept is proposed. By conditioning abnormal signals, the LOS rate estimation performance is increased. The process noise is also an important factor in the propagation phase. The analytical approach on a process noise component is performed and a reliable region for the filter is calculated based on the eigenvalue analysis. Some numerical simulations are performed to check the validity of suggested algorithm.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.194-195
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• 2009

According to the issue "global warming", many regulations and agreements with countries in the world are becoming set and it is being fulfill now. Under the progress of Post Kyoto Protocol agreement, It will be sure that Korea rave a duty to reduce $CO_2$ emission from 2013. For them, Korea have to make a strategies about the Climatic Change Convention for all industries. Recently, a great attention about $CO_2$ emission in the world is focused on port, shipping line and airline. Most countries are establishing policies to prevent environment from these industry fields, but Korea has not yet made for them. Thus, Korea need to collect $CO_2$ emission data not only the routes of container from port but also activities in the port. In this paper, an estimation of $CO_2$ emission under the route of container transportation at Korea by using O/D analysis will be addressed. And then, it will be used to make a optimal routes of container transportation which can reduce $CO_2$ emission in future.

• Journal of the Korean Geotechnical Society
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• v.38 no.8
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• pp.67-74
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• 2022

The setting of the target area for ground stability evaluation during ground excavation is categorized into theoretical and empirical estimation methods and numerical analysis methods. Generally, the applied theoretical and empirical estimation methods include those by Peck (1969), Caspe (1966), and Clough et al. (1990). The numerical analysis method comprehensively considered the current status of the task section (maximum excavation depth section, ground condition vulnerable section, etc.). It reflected the results of performing two and three-dimensional numerical analyses on the weakest section. Therefore, this study shows an example of setting the scope of influence when excavating the vertical and tunnel sections of a 000-line double-track private investment project through the above theoretical, empirical, and numerical analysis methods.