• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.273-280
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• 2008

Debris flow has been considered as one of the major natural hazards and possesses tens to hundreds times higher destructive potential than that of slope failure. In the past 5 years, its occurrence frequency was and is likely to increasing due to the global warming. Although various methods such as basin vegetation or structural dams can be implemented to counter measure the debris flow, these methods are not always the right answer to the problem when magnitude of debris flow is far bigger than could be defended. Land use regulations to avoid the hazard or early debris flow warning system to evacuate the expected inundated area can be more economical and practical actions for those cases. In this study, an early debris flow warning system composed of rainfall measuring device, debris flow sensing device and video camera is introduced. The system is designed to issue the warning when rainfall threshold is exceeded or debris flow is sensed by sensing device. Developed monitoring system can be used to cope promptly with the debris flow risk.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2004년도 제24회 동계학술대회 논문집
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• pp.264-287
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• 2004

The minimum royalty should have two objectives. One is to guarantee the minimum license payment and the other is to screen the eligible licensee to prevent the licensee`s strategic behavior. In the licensing contract for public-to-private technology transfer, the latter plays more important role than the former in viewpoint of the successful technology transfer and commercialization. However, the minimum royalty falls into a dilemma to increasing the risk on the part of licensee in case of failure in technology transfer and commercialization. In our study, ex-post option contract will be suggested as a risk sharing mechanism to overcome above dilemma. The ex-post option contract means the contract which the licensee has the option whether to go or not at the time of manufacturing stage. To proof the usefulness of ex-post option contract, it is shown in the study that expected utility of a licensor and a licensee can increase with a certain constraint, which depends on degree of uncertainty and licensee`s risk aversion, after introducing the ex-post option contract. In spite of this constraint, the usefulness of ex-post option contract may be highly appreciated because its constraint is quite normal case in the real world.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.186-192
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• 2022

Flow accelerated corrosion (FAC) is a type of pipe corrosion in which the pipe thickness decreases depending on the fluid flow conditions. In nuclear power plants, FAC mainly occurs in the carbon steel pipes of a secondary system. However, because the temperature of a secondary system pipe is over 150 ℃, in situ monitoring using a conventional ultrasonic non-destructive testing method is difficult. In our previous study, we developed a waveguide ultrasonic thickness measurement system. In this study, we applied a waveguide ultrasonic thickness measurement system to monitor the thinning of the pipe according to the change in pH. The Korea Atomic Energy Research Institute installed FAC-proof facilities, enabling the monitoring of internal fluid flow conditions, which were fixed for ~1000 h to analyze the effect of the pH. The measurement system operated without failure for ~3000 h and the pipe thickness was found to be reduced by ~10% at pH 9 compared to that at pH 7. The thickness of the pipe was measured using a microscope after the experiment, and the reliability of the system was confirmed with less than 1% error. This technology is expected to also be applicable to the thickness-reduction monitoring of other high-temperature materials.

• 아태비즈니스연구
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• 제9권4호
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• pp.157-180
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• 2018

This paper empirically analyzes how working conditions of employees and executives affect Korean companies' survival. To this end, a survival analysis based on the accelerated failure time model is conducted from the end of December 2012 to the end of September 2018 on the 2012 year-end financial data for corporations whose common stocks have ever been listed either in the KOSPI market or in the KOSDAQ market with fiscal year ending at the end of December. The analysis shows that the average wage level per employee and the number of executives relative to the number of employees threaten while the average duration of service for female employees prolongs firm survival. Here, the average wage level per employee has turned out to worsen firm survivability regardless of the gender of employees in question while the average duration of service improves firm survivability only in case the employees are female: the average duration of service for male employees or the entire employees has turned out not to have any statistically significant influence on firm survival. The average compensation per executive and the percentage of temporary employees have turned out not to have any statistically significant influence on firm survival while the percentage of female employees has shown statistically significant positive influence on firm survival in some, although not all, models employed in our study. These results are expected to be a good reference in the course of our reaching agreements regarding the improvement of working conditions either between firms and employees or among the members of the entire society.

• 한국지진공학회논문집
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• 제26권2호
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• pp.49-58
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• 2022

The 2017 Pohang earthquake caused severe damage to low-rise piloti buildings. The damage was caused mainly by column shear failure, and some core walls were as well. The damaged piloti buildings in Pohang City could be relieved if they were designed correctly according to the standards at that time. However, the post-earthquake investigation revealed design, construction, and permission problems. To solve the problems, the Piloti Building Structure Design Guidelines that include strict specifications were published in 2018. Separately, KDS 41 17 00, the seismic design standard for buildings, was enacted in 2019 and it included the guideline contents. Therefore, at least after the publication of the guidelines, piloti buildings, designed by the standard and guidelines, can be expected to possess better seismic performance than existing piloti buildings. To confirm this, the probability of exceedance for several damage state thresholds was estimated for existing and designed piloti buildings. As a result, the probability of damage of designed piloti buildings was very low compared to existing ones. Consequently, it was confirmed that the guideline and standard adequately supplement the structural fragility of existing piloti buildings.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.526-534
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• 2016

A MEMS solid propellant thruster array shall be operated within an allowable range of operating temperatures to avoid ignition failure by incomplete combustion due to a time delay in ignition. The structural safety of the MEMS thruster array under severe on-orbit thermal conditions can also be guaranteed by a suitable thermal control. In this study, we propose a thermal control strategy to perform on-orbit verification of a MEMS thruster module, which is expected to be the primary payload of the STEP Cube Lab mission. The strategy involves, the use of micro-igniters as heaters and temperature sensors for active thermal control because an additional heater cannot be implemented in the current design. In addition, we made efforts to reduce the launch loads transmitted to the MEMS thruster module at the system level structural design. The effectiveness of the proposed thermo-mechanical design strategy has been demonstrated by numerical analysis.

• 한국경영과학회지
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• 제24권4호
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• pp.27-47
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• 1999

Many enterprises are interested in using the IS development methodologies as a means of increasing system performance and solving the problems of delayed delivery time, excessive budget, and failure of integrated systems. Even if previous researches showed that the system productivity and quality improvement using the system development methodologies are very poor, we tried to find that the methodologies are meaningful as an innovative means for IS performance. We defined that the IS development methodology as a technical and managerial innovation for IS department. We intended to study the relationship between the implementation process of the IS development methodology divided into four steps and IS performance. A cross-sectional field survey with IS departments of domestic companies was conducted, and we used LISREL 8.12a to perform the structural equation model analysis and hypothesis verification. We found the meaningful relationship between the development methodology and qualitative performance. We reconfirmed that the relationship between the development methodology and quantitative performance is not meaningful as expected, which is the same result with the previous researches. But the qualitative performance affects very strongly to the quantitative performance. As a results, we suggest that IS managers and developers keep the principles of the IS development methodologies to get the quantitative performance through the qualitative performance improvement.

• 대한공간정보학회지
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• 제12권3호
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• pp.3-12
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• 2004

시설물관리시스템은 지자체에 도입된 보편적인 GIS활용체계라 할 수 있다. 지난 몇 년간 많은 지자체에서 시설물관리시스템을 개발하였는데 특히 상 하수도의 도로관리시스템 부분에 치중하였다. 여기에 도입된 시설물관리 범용프로그램의 개념은 지자체간의 개발업무에 있어 중복을 최소화하는 것이다. 최근 지자체에서는 분야별로 정보화의 한계를 인식하고 도시정보체계 구축으로 관심을 돌리고 있다. 따라서 본 연구에서는 지자체에서 도시정보체계를 구축할 수 있도록 지원하기 위한 범용프로그램의 활용가능성을 제시하고자 한다. 이렇게 함으로써 도시정보체계 구축에 있어 중복투자의 방지, 프로젝트 시간단축, 실패가능성의 최소화와 정보프로젝트의 활성화가 기대된다.

• 한국식생활문화학회지
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• 제33권2호
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• pp.199-205
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• 2018

This study has utilized the Quality Function Deployment (QFD) technique in order to plan the tangible (menu) and intangible (service) product of dumpling restaurant. The engineering characteristics of tangible products were classified into product planning, purchase management, production management, and information management based on the production system of foodservice. The engineering characteristics of intangible products were also classified into physical evidence, human interaction, and pre-communication based on the service operation and delivery system. As a result of analyzing the QFD, it was found that the customer hope the hygiene factor and response factor to be improved. It is analyzed that product planning, information management, and production management should be improved first in terms of engineering characteristics considering consumer needs. In the future, by utilizing the systematic product development process that the requirements of tangible and intangible product consumers are converted to the engineering characteristics, the development of competitive product within the market will be possible, and furthermore it is expected to be useful for reducing the unnecessary time and design costs due to failure of product development.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.673-682
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• 2018

One of the most widely used methods to estimate core damage during a nuclear power plant accident is containment radiation measurement. The evolution of severe accidents is extremely complex, leading to uncertainty in the containment dose rate (CDR). Therefore, it is difficult to accurately determine core damage. This study proposes to conduct uncertainty analysis of CDR for core damage assessment. First, based on source term estimation, the Monte Carlo (MC) and point-kernel integration methods were used to estimate the probability density function of the CDR under different extents of core damage in accident scenarios with late containment failure. Second, the results were verified by comparing the results of both methods. The point-kernel integration method results were more dispersed than the MC results, and the MC method was used for both quantitative and qualitative analyses. Quantitative analysis indicated a linear relationship, rather than the expected proportional relationship, between the CDR and core damage fraction. The CDR distribution obeyed a logarithmic normal distribution in accidents with a small break in containment, but not in accidents with a large break in containment. A possible application of our analysis is a real-time core damage estimation program based on the CDR.