• Applied Science and Convergence Technology
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• v.24 no.4
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• pp.84-89
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• 2015

The base pressure and outgassing rate of a mild steel chamber were measured and compared to those of a stainless steel chamber. A combined sputter-ion and non-evaporable getter pump with a nominal pumping speed of 490 l/s generated the base pressure of $2.7{\times}10^{-11}$ mbar in the mild steel chamber and $1.2{\times}10^{-10}$ mbar in the stainless steel chamber. The rate-of-rise measurements show that the mild steel has an extremely low outgassing rate of $2.6{\times}10^{-13}$ mbar $ls^{-1}cm^{-2}$, which is about one-order of magnitude smaller than the outgassing rate of the stainless steels. Vacuum annealing of the mild steel at $850^{\circ}C$ reduced the outgassing rate further to $8.8{\times}10^{-14}$ mbar $ls^{-1}cm^{-2}$, which was comparable to the outgassing rate of a heat treated stainless steel for extreme-high vacuum use.

• Korean System Dynamics Review
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• v.16 no.4
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• pp.5-30
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• 2015

This study analyses the inter-relationships between Safety Cultural Elements by System Dynamics approach. Base Frame for Safety Culture, which is originated from IAEA, NRC and INPO's Safety Culture Documents, helps to elaborate the Causal Loop Diagram of Safety Culture in Nuclear Power Plant(NPP). Also, the simulation results show that ownership of employees is degraded continually and adherence of technical standards is violated because workloads of the employees cannot be minimized and stress and time pressure maintains a high level in NPP.

• Mass Spectrometry Letters
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• v.2 no.3
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• pp.73-75
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• 2011

In the collisionally-activated dissociation of the proton-bound cluster ions of DNA base guanine (G) and cytosine (C), $G{\bullet}{\bullet}H^+{\bullet}{\bullet}C$, the abundance of [$CH^+$] ions was found to be higher than that of [$GH^+$] despite the fact that G has a higher proton affinity than C. This unexpected observation seems to demonstrate another example that the simple kinetic method scheme does not work. We suggest that a kinetic factor or detailed dynamics governing the proton transfer and dissociation should be carefully considered in the applications of the kinetic method to the proton affinity measurements.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1028-1032
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• 2005

Life cycle assessment(LCA) has been developed from the concept of life cycle thinking. Life cycle thinking implies that everyone in the whole chain of a product's life cycle, from cradle to grave, has a responsibility and a role to play, taking into account all the relevant external effects. LCA is an analytical tool for identifying environmental loads and assessing the environmental impact in the whole chain of a product's life cycle. In Europe and Japan, LCA and ecodesign study for railway industry have been actively carried out recently. However, LCA for railway industry in domestic is still infant. LCA is standardized in International Organization of Standardization(ISO), base on the ISO 14040 standards, 307 life cycle inventory(LCI) database for infrastructure and base materials have been established in total since 1999. Some of LCI database can use in performing LCA for trains and railway infrastructure, but still not enough to derive accurate LCA result. Therefore, railway oriented LCA methodology and LCI DB are needed to be developed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.528-544
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• 2015

Base Station Cooperation (BSC) has been a promising technique for combating the Inter-Cell Interference (ICI) by exchanging information through a high-speed optical fiber back-haul to increase the diversity gain. In this paper, we propose a novel pilot symbol assisted data fusion scheme for distributed Uplink BSC (UBSC) based on Differential Evolution (DE) algorithm. Furthermore, the proposed scheme exploits the pre-defined pilot symbols as the sample of transmitted symbols to constitute a sub-optimal Weight Calculation (WC) model. To circumvent the non-linear programming problem of the proposed sub-optimal model, DE algorithm is employed for searching the proper fusion weights. Compared with the existing equal weights based soft combining scheme, the proposed scheme can adaptively adjust the fusion weights according to the accuracy of cooperative information, which remains the relatively low computational complexity and back-haul traffic. Performance analysis and simulation results show that, the proposed scheme can significantly improve the system performance with the pilot settings of the existing standards.

• Explosives and Blasting
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• v.13 no.3
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• pp.19-30
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• 1995

NATM as method of tunneling has been applied to construction of domestic subway, roads, rail way, water way etc. Accordingly, we have NATM's many drafts and constructional results, but many problems and accidents have occurred under construction of tunnel using NATM for shortage of technical data. Poorness of constructional improvement, systemic inconsistency etc. Especially, everyone was shocked at Gupo's train wrecking accident lately. The purpose of this thesis is presentation of means for setting technical problems, by looking into Gupo's train wrecking accident and home records that applying NATM in tunneling failed, to minimize future safety accidents we find that the general problems of home fifteen sites having occured accidents is badly geological survey, nonconfirmationi of base rock's state, formal measuring management, shortage of specialists, systemical discrepancy and that disregarding NATM's rules makes general problems. The results of this study are Summarised as follows : 1. We advise repletion of design standards to practice crosshole test for confirming connected rock base on vertical section of tunnel. 2. We advise to practice pre0boring and pre-grouting for a weak layer difficult in applying NATM. 3. We advise systemic improvements that field servicer can construct tunnel of his own free will considering base rock's state at tunnel . 4. We advise that specialist, who can make a conduct and supervise above mentioned items as well as measuring management, should be posted at field.

• Journal of the Korean Society of Safety
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• v.9 no.4
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• pp.92-102
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• 1994

NATM as method of tunneling has been applied to construction of domestic subway, roads, rail way, water way etc. Accordingly we have NATM's many drafts and constructional results, but many problems and accidents have occurred under construction of tunnel using NATM for shortage of technical data, poorness of constructional improvement, systemic inconsistency etc. Especially, everyone was shocked at Gupo's train wrecking accident lately. The purpose of this thesis is presentation of means for settling technical problems, by looking into Gupo's train wrecking accident and home records that applying NATM in tunneling failed, to minimize future safety accidents we find that the general problems of home fifteen sites haying occured accidents is badly geological survey, nonconfirmation of base rock's state, formal measuring management, shortage of specialists, systemical discrepancy and that disregarding NATM's rules makes general problems. The results of this study are summarised as follows ; 1. We advise repletion of design standards to practice crosshole test for confirming connected rock base on vertical section of tunnel. 2. We advise to practice pre-boring and pre-grouting for a weak layer difficult in applying NATM. 3. We advise systemic improvements that field servicer can construct tunnel of his own free will considering base rock's state at tunnel. 4. We advise that specialist, who can make a conduct and supervise above mentioned items as well as measuring managements, should be posted at field.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.791-795
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• 2006

Urban transit is one of the most effective ways for efficient operation and construction of an urban transit by composition system which is liked originally such as rolling-stock, power, signal and infrastructure. Urban rail transit system is running in domestic, imports major equipments from advanced countries and setup for maintenance. But it takes long time because it does each organizations and lines. Also, signal, power and track system apply different standard by each construction organizations it causes an increasing construction of cost accordingly it desperately needs a systematic countermeasure. Therefore standard specification of urban transit have been establishing and operatingfor efficient operation of urban transit and base technology security that is populace ride to become a base of state economy. After track, power and signal system will be announced. Standard specification become more, the importance of administrationof standards is emphasized more. Specification administrator’s the importance which use a computing support tool recently in railroad part in embossed and is predicted to be more such forward. Therefore we propose the effective method of management with track, power signal system by constructed data-base system.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1387-1401
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• 2018

An aircraft impact (AI) on a nuclear power plant (NPP) is considered to be a beyond-design-basis event that draws considerable attention in the nuclear field. As some NPPs have already adopted the seismic isolation technology, and there are relevant standards to guide the application of this technology in future NPPs, a new challenge is that nuclear power engineers have to determine a reasonable method for performing AI analysis of base-isolated NPPs. Hence, dynamic influences of the seismic isolation on the vibration and structural damage characteristics of the base-isolated CPR1000 containment are studied under various aircraft loads. Unlike the seismic case, the impact energy of AI is directly impacting on the superstructure. Under the coupled influence of the seismic isolation and the various AI load, the flexible isolation layer weakens the constraint function of the foundation on the superstructure, the results show that the seismic isolation bearings will produce a large horizontal deformation if the AI load is large enough, the acceleration response at the base-mat will also be significantly affected by the different horizontal stiffness of the isolation bearing. These concerns require consideration during the design of the seismic isolation system.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.7-19
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• 2003

The airspace has to be designed considering the flight safety and economic efficiency of aircraft operators. The International Civil Aviation Organization(ICAO) published standards and recommended practices for safe design of the airspace. Each contracting country must follow the ICAO standards in designing the airspace for the utilization of civil aviation. Normally each member establishes its own standards and national aviation law for the safe and efficient design of the airspace, regarding the ICAO standards. However, our government has not developed yet clear and detailed standards and regulation system for airspace design. This might lead to aviation accidents and disputes between operators of aviation system This study is to review the characteristics of ICAO standards and a legal problem related to application of international standards for airspace design. Specifically this research analyzed the case of airspace design and operation of a domestic airport. The results of analysis are as follow: (1) per the safety of civil aviation, it is very required to establish national regulation system to follow ICAO standards in designing airspace, (2) It is also necessary to establish separate procedure for civil aircraft in military air base, when the aerodrome is co-used by military and civil aircraft. If the same procedure for military aircraft is applied to civil aircraft, it is necessary to make clear what the design concept is, (3) and the differences from ICAO standards have to be publicly known.