• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1570-1575
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• 2004

In order to evaluate the performance of fire-fighting agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams are experimentally investigated. The current research focuses on the destruction of a fire-fighting foam subjected to heat radiation. A simple repeatable test for fire-protection foams subjected to fire radiation is developed. This test involves foam generation equipment, a fire source for heat generation, repeatable test procedures, and data acquisition techniques. Results of the experimental procedure indicated that each thermocouple within the foam responded in a similar manner and gradually to a temperature of $15^{\circ}C{\sim}20^{\circ}C$. At this point, each trace generally rises to a temperature of approximately $90^{\circ}C$. The temperature gradient in the foam as time passes increases with increased foam expansion ratio. In addition, it is determined that the temperature gradient along the foam for depth decreases with increased foam expansion ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.97-98
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• 2006

High current behaviors of the grounded gate extended drain N-type metal-oxide-semiconductor field effects transistor (GG_EDNMOS) electro-static discharge (ESD) protection devices are analyzed. Simulation based contour analyses reveal that combination of BJT operation and deep electron channeling induced by high electron injection gives rise to the 2-nd on-state. Thus, the deep electron channel formation needs to be prevented in order to realize stable and robust ESD protection performance. Based on our analyses, general methodology to avoid the double snapback and to realize stable ESD protection is to be discussed.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.526-533
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• 1997

Reliability of fire protection systems is often discussed, written about, and even put into codes and standards. However, reliability is seldom considered for the fire protection system as a whole. Why does this happen and why should the designer consider the system as a whole\ulcorner Existing codes and standards incorporate the concept of reliability usually In the form of key component redundancy for some parts of a system. The "Fire Safety Concepts Tree" presented in the National Fire Protection Association Guide 550, Guide to the Fire Safety Concepts Tree, provides a starting point for considering the performance of a water based fire suppression system. Considering fire protection objectives for water based fire suppression systems, means of evaluating system reliability can be developed. This development requires identification of system components that are significant to the overall system reliability.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.25-38
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• 2023

Instrumentation and control systems measure and control various variables of nuclear facilities to operate nuclear power plants safely. A diverse protection system, a representative instrumentation and control system, generates a reactor trip and turbine trip signal by high pressure in a pressurizer and containment to satisfy the design requirements 10CFR50.62. Also, it generates an auxiliary feedwater actuation signal by low water levels in steam generators. Cybersecurity has become more critical as digital technology is gradually applied to solve problems such as performance degradation due to aging of analog equipment, increased maintenance costs, and product discontinuation. This paper analyzed possible cybersecurity threat scenarios in the diverse protection system using attack trees. Based on the analyzed cybersecurity threat scenario, we calculated the probability of attack occurrence and confirmed the cybersecurity risk in connection with the asset value.

• International Journal of Quality Innovation
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• v.6 no.1
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• pp.24-34
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• 2005

This research topic evaluates the effectiveness and importance of environmental protection in the 21st century in light of the increasing demand on the earth's natural resources and the pressures on economic and industrial development to provide dynamic power. As the world and our fellow citizens become more conscious of environmental protection, companies are under greater pressure whilst pursuing economic growth. Therefore, domestic manufacturers have been devoting efforts to promote environmental management. This research conducts survey using questionnaires on the operational performance of the manufacturers who have ISO 14000 series accreditation and certification. The survey considers five dimensions/functions within a manufacturer, financial management, human resources management, production management, and marketing management. A total of 35 indices are used for analysis of the effects that the location, history, industry, number of employees, amount of capital, and revenue may have on the performance. This research targets the manufacturers approved of ISO 14000 series certification by Environment Administration Association. The statistical methods deployed are descriptive statistics, T-test, and single factor analysis of variance used for analysis. The conclusions reveal that a certain level of performance has been achieved in every dimension. After T-test, all the indices have reached a significant level. The indications are that ISO 14001 benefits all manufacturers the level of benefits however varies from company to company.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.111-115
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• 2016

Background: The scattered photons cause reduction of the contrast of radiographic image and it results in the degradation of the quality of the image. In order to acquire better quality image, an anti-scattering x-ray gird should be equipped in radiography system. Materials and Methods: The X-ray anti-scattering grid of the inclined type based on the hybrid concept for that of parallel and focused type was tested by MCNP code. The MCNPX 2.7.0 was used for the simulation based test. The geometry for the test was based on the IEC 60627 which was an international standard for diagnostic X-ray imaging equipment-Characteristics of general purpose and mammographic anti-scatter grids. Results and Discussion: The performance of grids with four inclined shielding material types was compared with that of the parallel type. The grid with completely tapered type the best performance where there were little performance difference according to the degree of inclination. Conclusion: It was shown that the grid of inclined type had better performance than that of parallel one.

• Fire Science and Engineering
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• v.22 no.4
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• pp.76-84
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• 2008

Researches on fire resistant performance of primary structural elements such as columns and beams located at above the ground have actively been doing than those located at the below the ground from many researchers. But the structural elements such as columns at underground is very important in aspects of not only structural performance but also fire environment. The columns at the basement carry all the structural loads from the above and that means very critical in fire circumstances than that located at above the grounds. To evaluate the fire resistance performance of primary structural elements located at below the ground we conducted several sorts of surveys that contained fire regulations from several countries and structural types, materials and status of passive fire protection methods.

• Journal of Radiation Protection and Research
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• v.34 no.2
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• pp.77-81
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• 2009

An Area Radiation Monitoring System (ARMS) ionization chamber, which had an 11.8 L active volume, was fabricated and performance-tested at KAERI. Low leakage currents, linearities at low and high dose rates were achieved from performance tests. The correlation coefficients between the ionization currents and the dose rates are 1 at high dose rate and 0.99 at low dose rate. In this study, an integration-type ARMS ionization chamber was tested over a year for an evaluation of its long-term stability at a radioisotope (RI) repository of the Young-gwang nuclear power plant. The standard deviation of dose rate of 1 day data and over a 100-days mean value were 6.2 $\mu$R/h and 2.9 $\mu$R/h, respectively. The fabricated ARMS ionization chamber showed stable performance from the results of the long-term tests. Design and performance characteristics of the fabricated ionization chamber for the ARMS from performance-tests are also addressed.

• Korean small business review
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• v.41 no.2
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• pp.1-24
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• 2019

This paper seeks to explore the effects of search strategies on innovation performance in the context of small and medium enterprises. The empirical results of 3,398 Korean SMEs demonstrate that there is a substitutive relationship between search depth and search width, and this substitutive relationship is weakened when a firm possesses collaboration experience. Furthermore, although these two types of search enhance innovation performance, the impact of search depth is greater than that of search width. The positive effect of search width on innovation performance is weakened when the firm adopts formal information protection mechanisms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.9
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• pp.1019-1027
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• 2014

Vehicle-into-pedestrian traffic accidents show a very high mortality rate compared to their frequency of occurrence. Throughout the world, governments and insurance companies tend to establish and implement new safety standards for pedestrian protection. In order to improve the performance of pedestrian protection, the Korean government has evaluated the pedestrian safety of vehicles under the Korea New Car Assessment Program (K-NCAP) since 2007. The pedestrian protection performance has improved gradually, but it remains insufficient. A pedestrian protection system consisting of a hood lift system and a pedestrian airbag can be a solution to pedestrian safety. A pedestrian airbag design procedure based on a newly defined design scenario is introduced to reduce the head injury criterion of pedestrians. The proposed design scenario is discussed from a practical viewpoint and applied to manufacture pedestrian protection systems.