• Knowledge Management Research
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• v.17 no.3
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• pp.117-136
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• 2016

External knowledge search is critical to expand the firm's knowledge base, increasing the innovation performance. However, prior literature has paid less scholarly attention on the boundary condition of the search activity. In particular, the few literatures on the contingency factors are either conceptual or focus on the firm characteristics such as resources and capability. In this regard, this study argues the negative moderating effect of knowledge protection and environmental uncertainty of a firm on the positive relationship between external knowledge search and innovation performance, because these contingency factors hamper the reciprocity and the mutual trust between the firm and its external partner that provides knowledge needed in the innovation process. The empirical analysis is based on the sample drawn from Korean Innovation Survey, provided by STEPI in Korea. The sample consists of 1,637 respondent firms that experienced product innovation during the survey period. We could find statistically supporting results for the negative moderating effect on the positive relationship between external knowledge search and innovation performance. This study extends the academic debate on the boundary conditions of external knowledge search and provides managerial implications for successful product innovation.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.169-169
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• 2009

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.81-83
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• 2005

The Reactor Protection System (RPS) is a very important system in a nuclear power plant because the system shuts down the reactor to maintain the reactor core integrity and the reactor coolant system pressure boundary if the plant conditions approach the specified safety limits. This paper describes the unavailability assessment of a digital reactor protection system using the fault tree analysis technique. The fault tree technique can be expressed in terms of combinations of the basic event failures. In this paper, a prediction method of the hardware failure rate is suggested for a digital reactor protection system. and applied to the reactor protection system being developed in Korea.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.369-382
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• 2003

Natural resources managers have considered the landscape without detailed consideration of aesthetic values of the landscape and geomorphological significance of unique landforms. Since EIA system was introduced in 1981, values associated with landscape protection have been neglected at best compared with those values traditionally attributed to environmental protection, including clean air, water quality and species protection. Black top highways are being built without consideration of harmful effects to the sea cliffs. Sea walls and tetrapod are being installed to protect the coastal towns and fish markets for tourist. However, beach itself are experiencing accelerated erosion due to the shortage of proper coastal engineering expertise. Hotels and condominiums are under construction on a massive scale around the national parks, which substitute the scenic ridges with concrete profiles. To protect the scenic beauty of national parks, their design and construction material should be more harmonious with the surroundings. Therefore, visual impact assessment should be applied both within the national park boundary and beyond to enhance the aesthetic values of national parks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.237-243
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• 2018

Performance-oriented design has been introduced in fire protection design, and various efforts have been made to minimize the damage caused by fire in the design stage. We conducted a study to provide information for reasonable design factors using a Fire Dynamic Simulation code provided by the NIST on boundary width and amount of supply. This paper shows that using a living-room air-supply system in a large space and dividing the space by a ventilation boundary are the two factors that are considered to have the greatest influence on the design of the living room ventilation. The results show that for performance-based design, the width of the ventilation boundary is designed to be the maximum limit in the initial design. It is judged that reasonable air volume determination should be made through various methods.

• Corrosion Science and Technology
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• v.16 no.6
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• pp.294-297
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• 2017

For the longer service life of steel pile, cathodic protection is selected sometimes at corrosive environment. The cathodic protection design improvement was investigated in this study. The current demand for cathodic protection was calculated from the potentiostatic current monitoring of the steel specimen in the deaerated soil samples. In this study, the current distribution was studied using the Boundary Element Method (BEM) and the Finite Element Method (FEM) numerical analysis methods. The optimum layout of the anode was developed and confirmed by numerical analysis. Under the conventional design of the anode, the length of the anode hole is same as the pile length. We found that, at the bottom end of the pile, the current density is too high. When the anode hole length was 80% of the pile length, the current consumption at the end was reduced. The construction cost of anode hole drilling was decreased about 20%, as compared to the conventional design. Furthermore, the life of the anode materials could be extended by reducing the current consumption at the end section. Using this approach, the construction cost was reduced significantly without any under-protection area on the steel piles.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.191-196
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• 1996

The potential value of the Application Specific Integrated Circuits(ASIC's) in safety systems of Nuclear Power Plants(NPP's) is being increasingly recognized because they are essentially hardwired circuitry on a chip, the reliability of the system can be proved more easily than that of software based systems which is difficult in point of software V&V(Verification and Validation). There are two types of ASIC, one is a full customized type, the other is a half customized type. PLD(Programmable Logic Device) used in this paper is a half customized ASIC which is a device consisting of blocks of logic connected with programmable interconnections that are customized in the package by end users. This paper describes the RPS(Reactor Protection System) composed of ASICs which provides emergency shutdown of the reactor to protect the core and the pressure boundary of RCS(Reactor Coolant System) in NPP's. The RPS is largely composed of five logic blocks, each of them was implemented in one PLD, as the followings. A). Bistable Logic B). Matrix Logic C).Initiation Logic D). MMI(Man Machine Interface) Logic E). Test Logic.

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.291-298
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• 2003

The KN-12 transport cask has been designed to transport 12 PWR spent nuclear fuel assemblies and to comply with the regulatory requirements for a Type B(U) package. The containment boundary of the cask is defined by a cask body, a cask lid, lid bolts with nuts, O-ring seals and a bolted closure lid. The containment vessel for the cask consists of a forged thick-walled carbon steel cylindrical body with an integrally-welded carbon steel bottom and is closed by a lid made of stainless steel, which is fastened to the cask body by lid bolts with nuts and sealed by double elastomer O-rings. In the cask lid an opening is closed by a plug with an O-ring seal and covered by the bolted closure lid sealed with an O-ring. The cask must maintain a radioactivity release rate of not more than the regulatory limit for normal transport conditions and for hypothetical accident conditions, as required by the related regulations. The containment requirements of the cask are satisfied by maintaining a maximum air reference leak rate of $2.7{\times}10^{-4}ref.cm^3s^{-1}$ or a helium leak rate of $3.3{\times}10^{-4}cm^3s^{-1}$ for normal transport conditions and for hypothetical accident conditions.

• Journal of radiological science and technology
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• v.46 no.1
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• pp.23-28
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• 2023

The purpose of this study is to see the radiation protection effect of the oral injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts on the small intestine and uterus of female SD Rat as a natural radiation protection agent. The experimental group was divided into four groups: Normal Control group (NC group), Injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts group (DZ group), irradiated group after injecting Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts (DZ+IR group). The whole body of SD Rat was irradiated with gamma-ray 10Gy, and the administration of oral Dendranthema zawadskii var. latilobum (Maxim.) Kitam. Extract was 2 cc (71.56 mg/day/kg) once a day for 2 weeks. For this study, chages in blood cell levels, SOD assay, small intestine and uterus were observed. In the 21st white blood cell level, the DZ+IR group recovered to a normal level, and the IR group didn't. The IR group villus length was lower than other groups on Day 1. IR group was partially recovered, and DZ+IR group was recovered like the NC group on Day 21. In the case of the first-day endometrium, the IR group was thin and the boundary was cloudy, and the DZ+IR group was thicker and the boundary was clearer than the IR group. Day 21 IR group still did not recover, and DZ+IR group recovered like NC group. This is believed to have radiation protection effects in the blood cells and small intestine and uterus of the irradiated female SD Rat, and is expected to be useful for the study of natural radiation protection materials.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.236-245
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• 2016

In a reactor coolant system of a nuclear power plant (NPP), an overpressure protection system keeps pressure in the loop within 110% of design pressure. However if the system does not work properly, pressure in the loop could elevate hugely in a short time. It would be seriously disastrous if a weak point in the pressure boundary component bursts and releases radioactive material within the containment; and it may lead to a leak outside the containment. In this study, a gross deformation that leads to a burst of pressure boundary components was investigated. Major components in the primary pressure boundary that is structurally important were selected based on structural mechanics, then, they were used to study the burst pressure of components by finite element method (FEM) analysis and by number of closed forms of theoretical relations. The burst pressure was also used as a metric of design optimization. It revealed which component was the weakest and which component had the highest margin to bursting failure. This information is valuable in severe accident progression prediction. The burst pressures of APR-1400, AP1000 and VVER-1000 reactor coolant systems were evaluated and compared to give relative margins of safety.