• Nuclear Engineering and Technology
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• v.39 no.2
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• pp.103-110
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• 2007

The High Temperature Gas-cooled Reactor (HTGR) possesses inherent safety features and is recognized as a representative advanced nuclear system for the future. Based on the success of the HTR-10, the long-time operation test and safety demonstration tests were carried out. The long-time operation test verifies that the operation procedure and control method are appropriate for the HTR-10 and the safety demonstration test shows that the HTR-10 possesses inherent safety features with a great margin. Meanwhile, two new projects have been recently launched to further develop HTGR technology. One is a prototype modular plant, denoted as HTR-PM, to demonstrate the commercial capability of the HTGR power plant. The HTR-PM is designed as $2{\times}250$ MWt, pebble bed core with a steam turbine generator that serves as an energy conversion system. The other is a gas turbine generator system coupled with the HTR-10, denoted as HTR-10GT, built to demonstrate the feasibility of the HTGR gas turbine technology. The gas turbine generator system is designed in a single shaft configuration supported by active magnetic bearings (AMB). The HTR-10GT project is now in the stage of engineering design and component fabrication. R&D on the helium turbocompressor, a key component, and the key technology of AMB are in progress.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.195-196
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• 2019

It It is not easy to reduce the operation costs at a time when it is hard to expect increase sales due to growing economic uncertainties. For logistics centers, which need to keeps their competitive advantage in the market by raising service levels at low cost, it is essential to drastically improve service levels at low cost. This study suggests that KPI (Key Performance Indicator) analysis should determine whether efficient logistics operation is being performed for the entire process of the logistics operation system. And also we suggests that each item should be set up, measured, and improved so that customer satisfaction can be increased based on performance indicators.

• Progress in Superconductivity and Cryogenics
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• v.23 no.3
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• pp.55-59
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• 2021

A thermoelectric cooler (TEC) is promising as an alternative refrigeration technology for the sake of its inherent advantages; no-moving parts and refrigerant-free in its operation. Due to the compactness, reliability and excellence in temperature stability, TECs have been widely used for small cooling devices. In recent years, thermoelectric devices have been attractive technologies that not only serve the needs of cooling and heating applications but also meet the demand for energy by recycling waste heat. In this research paper, multistage TEC is proposed as a concept of demonstrating the idea of transient cooling technology. The key idea of transient cooling is to harnesses the thermal mass installed at the interfacial level of the stages. By storing heat temporally at the thermal mass, the multistage TEC can readily reach lower temperatures than that by a steady-state operation. The multistage TEC consists of four different sizes of thermoelectric modules and they are operated with an optimized current. Once the cold-part of the uppermost stage is reached at the no-load temperature, the current is successively supplied to the lower stages with a certain time interval; 25, 50 and 75 seconds. The results show the temperatures that can be ultimately reached at the cold-side of the lowermost stage are 197, 182 and 237 K, respectively. It can be concluded that the timing or total amount of the current fed to each thermoelectric module is the key parameter to determine the no-load temperature.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.831-835
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• 2005

In a signal control of the railway system, the first objective is to guarantee a safety of the train operation, and the second is to increase a frequency(a capability of the transportation) of the train operation. In order to express the capability of the transportation a terminology what is called a railroad line capacity is employed. The railroad line capacity means a maximum frequency of the train operation in a possible schedule of the one way operation for one day. During the last several years an improvement in the facilities of the train operation (railroad line extension, improvement in the stations, improvement in the signal facilities) has been achieved to increase the railroad line capacity. In this paper the authors deal with the case analysis which try to shorten headway and which has an impartible relation with increasing of the railroad capacity

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.111-116
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• 2021

Normal Operation Safety Survey (NOSS) is a safety management tool used by air traffic control organizations to measure data related to threats and errors to proactively prevent accidents before they occur. NOSS was developed to be applied to the air traffic control field according to the concept of Line Operation Safety Audit (LOSA) conducted by airlines to reduce human errors in the cockpits. Safety management based on data is crucial for the prevention of control-related accidents, and the competency of observers for this is important for the successful implementation of NOSS. Based on LOSA implementation experiences and expert interviews, this paper introduces the international NOSS methods and discusses the key factors required for effective observation and the implementation methods and implications of NOSS observer training.

• Journal of Information Technology Services
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• v.5 no.2
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• pp.39-58
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• 2006

The e-business strategies ultimately pursue creating the maximal value for customers through the competitive advantages and business opportunities newly created on the basis of information technologies. For the realization of e-business strategies, the successful implementation and operation of e-business system must be the crucial activities in and out of an organization. Therefore, in physical world, there were lots of interests that what kind of key factors can lead the success of e-business system. Moreover, in the field of academia also, there have been many research results for investigating and finding out the key success factors for e-business system. However, the perceptual level of the significance of key success factors that organization members perceive can be changed over each phase of system life cycle such phases as introduction, growth, maturity, and decline. This study investigated that there might be significant differences in the perceptual level regarding importance of success factors among phases of system life cycle.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.143-161
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• 2005

The e-business strategies ultimately pursue creating the maximal value for customers through the competitive advantages and business opportunities newly created on the basis of information technologies. For the realization of e-business strategies, the successful implementation and operation of e-business system must be the crucial activities in and out of an organization. Therefore, in physical world, there were lots of interests that what kind of key factors can lead the success of e-business system. Moreover, in the field of academia also, there have been many research results for investigating and finding out the key success factors for e-business system. However, the perceptual level of the significance of key success factors that organization members perceive can be changed over each phase of system life cycle such phases as introduction, growth, maturity, and decline. This study investigated that there might be significant differences in the perceptual level regarding importance of success factors among phases of system life cycle.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.171-184
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• 2005

The e-business strategies ultimately Pursue creating the maximal value for customers through the competitive advantages and business opportunities newly created on the basis of information technologies. For the realization of e-business strategies, the successful implementation and operation of e-business system must be the crucial activities in and out of an organization. Therefore, in physical world, there were lots of interests that what kind of key factors can lead the success of e-business system. Moreover, in the field of academia also, there have been many research results for investigating and finding out the key success factors for e-business system. However, the perceptual level of the significance of key success factors that organization members perceive can be changed over each phase of system life cycle such phases as introduction, growth, maturity, and decline. This study investigated that there might be significant differences in the perceptual level regarding importance of success factors among phases of system life cycle.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.259-267
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• 2004

Enterprise must establish a properly competitive strategy according to environmental changes and international competitions. It is necessary to develop the strategy of competitive power for an efficient operation as well as system, industry, product and price competitions. This paper aims to propose a choice method of Competitive Power Key Factors which can be applied to unit parts and finished products, construction products, soft wear products based on Reliability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2517-2524
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• 2012

This paper describes an efficient implementation of KS(Korea Standards) block cipher algorithm ARIA. The ARIA crypto-processor supports three master key lengths of 128/192/256-bit and four modes of operation including ECB, CBC, OFB and CTR. A hardware sharing technique, which shares round function in encryption/decryption with key initialization, is employed to reduce hardware complexity. It reduces about 20% of gate counts when compared with straightforward implementation. The ARIA crypto-processor is verified by FPGA implementation, and synthesized with a $0.13-{\mu}m$ CMOS cell library. It has 46,100 gates on an area of $684-{\mu}m{\times}684-{\mu}m$ and the estimated throughput is about 1.28 Gbps at 200 MHz@1.2V.