• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2789-2802
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• 2020

Small Modular Reactors (SMRs) are attracting wide attention due to their outstanding performance, extensive studies have been carried out for lead-based fast reactors (LFRs) that cooled with Lead or Lead-bismuth (LBE), and small modular natural circulation LFR is one of the promising candidates for SMRs and LFRs development. One of the challenges for the design small modular natural circulation LFR is to master the natural circulation thermal-hydraulic performance in the reactor primary circuit, while the natural circulation characteristics is a coupled thermal-hydraulic problem of the core thermal power, the primary loop layout and the operating state of secondary cooling system etc. Thus, accurate predicting the natural circulation LFRs thermal-hydraulic features are highly required for conducting reactor operating condition evaluate and Thermal hydraulic design optimization. In this study, a thermal-hydraulic analysis code is developed for small modular natural circulation LFRs, which is based on several mathematical models for natural circulation originally. A small modular natural circulation LBE cooled fast reactor named URANUS developed by Korea is chosen to assess the code's capability. Comparisons are performed to demonstrate the accuracy of the code by the calculation results of MARS, and the key thermal-hydraulic parameters agree fairly well with the MARS ones. As a typical application case, steady-state analyses were conducted to have an assessment of thermal-hydraulic behavior under nominal condition, and several parameters affecting natural circulation were evaluated. What's more, two characteristics parameters that used to analyze natural circulation LFRs natural circulation capacity were established. The analyses show that the core thermal power, thermal center difference and flow resistance is the main factors affecting the reactor natural circulation. Improving the core thermal power, increasing the thermal center difference and decreasing the flow resistance can significantly increase the reactor mass flow rate. Characteristics parameters can be used to quickly evaluate the natural circulation capacity of natural circulation LFR under normal operating conditions.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2230-2245
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• 2023

KANT (KAIST Advanced Nuclear Tachygraphy) is a PWR core simulator recently developed at Korea Advance Institute of Science and Technology, which solves three-dimensional steady-state and transient multigroup neutron diffusion equations under Cartesian geometries alongside the incorporation of thermal-hydraulics feedback effect for multi-physics calculation. It utilizes the standard Nodal Expansion Method (NEM) accelerated with various Coarse Mesh Finite Difference (CMFD) methods for neutronics calculation. For thermal-hydraulics (TH) calculation, a single-phase flow model and a one-dimensional cylindrical fuel rod heat conduction model are employed. The time-dependent neutronics and TH calculations are numerically solved through an implicit Euler scheme, where a detailed coupling strategy is presented in this paper alongside a description of nodal equivalence, macroscopic depletion, and pin power reconstruction. For validation of the steady, transient, and depletion calculation with pin power reconstruction capacity of KANT, solutions for various benchmark problems are presented. The IAEA 3-D PWR and 4-group KOEBERG problems were considered for the steady-state reactor benchmark problem. For transient calculations, LMW (Lagenbuch, Maurer and Werner) LWR and NEACRP 3-D PWR benchmarks were solved, where the latter problem includes thermal-hydraulics feedback. For macroscopic depletion with pin power reconstruction, a small PWR problem modified with KAIST benchmark model was solved. For validation of the multi-physics analysis capability of KANT concerning large-sized PWRs, the BEAVRS Cycle1 benchmark has been considered. It was found that KANT solutions are accurate and consistent compared to other published works.

• 해양환경안전학회지
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• 제25권6호
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• pp.717-725
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• 2019

본 연구는 해운기업의 핵심역량이 해당 기업에서 승선실습을 마친 실습생들의 만족도와 이것이 졸업 후 승선 기업선택 및 장기승선에 미치는 영향을 연구하는데 있다. 이를 위해 선행연구 등을 바탕으로 설문 문항을 설정하여 위탁실습을 마친 실습생 211명을 대상으로 설문조사를 수행하고 가설을 설정하여 검증한 결과, 다음과 같은 연구 결과를 도출하였다. 첫째, 기업의 핵심역량에 해당하는 가치성과 지속성은 승선 실습의 만족도에 모두 유의한 영향을 미치며, 이들에 대한 영향력은 각각 32.4 %와 32.7 %로 나타났다. 둘째, 승선실습 만족도는 졸업 이후 승선기업 선택에 유의한 영향을 미치며, 이들에 대한 영향력은 49.7 %로 나타났다. 셋째, 승선실습의 만족도와 장기 승선간에는 4.5 % 수준의 낮은 영향력이 형성되고 있는 것으로 조사되었다. 넷째, 승선기업 선택과 장기 승선간에는 74 %의 높은 영향력이 형성중인 것으로 나타났다. 이와 같은 연구결과를 토대로 해운기업은 선박관리 능력 향상을 위해 핵심역량을 증대시키고, 우수한 해기인력을 수급받기 위한 실습생 만족도 향상 노력이 필요하다는 것을 확인하였다.

• 기술혁신연구
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• 제11권1호
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• pp.125-145
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• 2003

In the knowledge-based economy, the accumulation of technological knowledge is undoubtedly the core competency to reinforce the competitiveness of individual firms and to raise the innovation capability of social and economic systems. Thus far, however, only single or fragmentary indicators, such as R&D expenditure, R&D stock, the number of researchers and the number of R&D employees have been adopted to measure the amount of technological knowledge. In this research, we suggest an approach for aggregating and structuring respective indicators. Applying correlation and factor analysis, we examine the relationship among nine conventional proxy measures for technological knowledge and present a new approach for gauging an aggregated measure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.52-55
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• 2004

Digital communication networks have become a core technology in advanced building automation systems. BACnet(${\underline{B}}uilding$ ${\underline{A}}utomation$ and ${\underline{C}}ontrol$ ${\underline{net}}works$) is a standard data communication protocol designed specifically for building automation and control systems. BACnet adopts Master-Slave/Token-Passing (MS/TP) protocol as one of its field level networks. In this study, we introduce a method of implementing bandwidth allocation scheme in the MS/TP protocol. The bandwidth allocation scheme improves the capability of real-time communication of the original MS/TP protocol. The bandwidth allocation scheme introduced in this paper can be easily implemented in the existing MS/TP protocol with a slight modification. In this study, we actually developed the hardware and firmware of MS/TP module in which bandwidth allocation scheme is implemented.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.198-204
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• 2007

본 연구는 핵심역량 지향성을 중심으로 고찰한 IT 아웃소싱 성공요인 및 결과에 관한 것으로, 아웃소싱 프로세스 관리역량과 기업의 핵심역량 지향성이 IT 아웃소싱된 업무 복잡도와 아웃소싱 성과에 영향을 미치는 지, 그리고 아웃소싱 프로세스 관리역량이 기업의 핵심역량 지향성과 아웃소싱 성과의 관계를 매개하는 효과가 있는지에 대한 실증 연구이다. 따라서 본 연구는 독립변수로 핵심역량 지향성과 종속변수로 아웃소싱된 업무 복잡도 그리고 매개변수로 아웃소싱 프로세스 관리역량을 사용하였다. 국내 IT 아웃소싱 협회에 등록된 회사의 IT 부서를 대상으로 200 개의 데이터를 확보하였고 공분산 구조방정식 모델로 분석하였다. 연구결과, IT 아웃소싱 프로세스 관리역량은 핵심역량 지향성이 아웃소싱된 업무 복잡도와 아웃소싱 성과에 미치는 영향을 매개하는 것으로 밝혀졌다. 그리고 핵심역량 지향성은 아웃소싱의 성과에 긍정적인 영향을 미치지만 아웃소싱된 업무 복잡도엔 유의한 영향을 미치지 않는 것으로 나타났다.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2005년도 27회 하계학술발표회 논문집
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• pp.116-139
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• 2005

ICT(information and communication technology) has played a pivotal role in the world economy, and the out look for ICT has improved markedly. One of the noticeable characteristics in the ICT sector Is the global rationalization of its technology and service. Specialization on the specific ICT capability is a pressing problem for many countries. Along the line of classical innovation cluster and network studies, this paper suggests a way to find and analyze the role of core technologies on the ICT network First, technology network is constructed by using patent citation data from USPTO. Then, a couple of cluster is generated by K-means clustering technique. Finally, brokerage analysis is applied to manifest the role of principal technologies. The network visualization and some stylized facts on dynamics are briefly given altogether Based on the role and relationship of technologies across clusters, it is expected that this research could contribute to the ICT cluster formation and the vision-making for ICT specialization at the viewpoint of technology Policy.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.230-234
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• 1995

The loss of offsite power test was successfully performed on YGN 4 to demonstrate that the reactor can be shutdown and the RCS can be maintained in a hot standby condition following a loss of all offsite Alternating Current (AC) power. Following the loss of main generator and all offsite AC power, the ensile emergency diesel generators were automatically started and the plant was stabilized via natural circulation. Plant conditions were maintained in hot standby for at least 30 minutes before offsite power was restored. Thus, the capability of equipment, controls and instrumentation necessary to remove decay heat from the core using only ensile emergency power was demonstrated, thereby satisfying all objectives and acceptance criteria of the test.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.431-434
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• 2001

Knowledge discovery in databases(KDD) is the process for extracting valid, novel, potentially useful and understandable knowledge form real data. There are many academic and industrial activities with new technologies and application areas. Particularly, data mining is the core step in the KDD process, consisting of many algorithms to perform clustering, pattern recognition and rule induction functions. The main goal of these algorithms is prediction and description. Prediction means the assessment of unknown variables. Description is concerned with providing understandable results in a compatible format to human users. We introduce an efficient data mining algorithm considering predictive and descriptive capability. Reasonable pattern is derived from real world data by a revised neural network model and a proposed fuzzy rule extraction technique is applied to obtain understandable knowledge. The proposed neural network model is a hierarchical self-organizing system. The rule base is compatible to decision makers perception because the generated fuzzy rule set reflects the human information process. Results from real world application are analyzed to evaluate the system\`s performance.

• 대한산업공학회지
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• 제32권4호
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• pp.358-368
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• 2006

The significance of intellectual property in the knowledge-based society has been increasing and as a result, the patent customer's demand for a top quality patent administration service has increased as well. Therefore, Korean Intellectual Property Office(KIPO) adopted 6 sigma as a tool for KIPO's innovation to improve the quality of patent administration and enhance customer satisfaction. KIPO's steadfast promotion of 6 sigma resulted in many successful outcomes such as improvement of policy and service process from customer's point view, streamlining the administrative procedures, increased work efficiency, capability enhancement of core personnel, and so on. Since 6 sigma has proved itself to be equipped with features suitable for innovation in public sector, it can be used as an extensible innovation tool to meet the challenges in rapidly changing administration environment and to achieve a competitive edge.