• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.764-769
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• 2022

The United Arab Emirates is currently building and operating four units of the APR-1400 developed by a South Korean vendor, Korea Electric Power Corporation (KEPCO). This paper attempts to perform APR-1400 reactor core analysis by using the well-known two-step method. The two-step method was applied to the APR-1400 first cycle using the open-source nodal diffusion code, KOMODO. In this study, the group constants were generated using CASMO-4 fuel transport lattice code. The simulation was performed in Hot Zero Power (HZP) at steady-state and transient conditions. Some typical parameters necessary for the Nuclear Design Report (NDR) were evaluated in this paper, such as effective neutron multiplication factor, control rod worth, and critical boron concentration for steady-state analysis. Other parameters such as reactivity insertion, power, and fuel temperature changes during the Reactivity Insertion Accident (RIA) simulation were evaluated as well. The results from KOMODO were verified using PARCS and SIMULATE-3 nodal core simulators. It was found that KOMODO gives an excellent agreement.

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.189-189
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• 2005

• International conference on construction engineering and project management
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• 2007.03a
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• pp.417-423
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• 2007

This paper describes how using the XPS Document technologies of Windows Vista support and enhances interactions with the structural design and construction process. It illustrates the document workflows and the document life cycle in a typical construction base knowledge system. It provides engineers and decision makers and implementers with information about this new technology and how they can apply it to their design and construction models. The paper also highlights opportunities for the new format of data exchange in the recent efforts to develop National Management System Standards for Transportation Applications to benefit from these emerging technologies.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.109-112
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• 2021

매년 슈퍼컴퓨터를 표적으로 공격이 증가하고 있고, 공격의 방식은 날로 진화하고 있다. 슈퍼컴퓨터를 대상으로 하는 공격에 대응하기 위해 기존의 연구는 공격 특성을 분석하여 맞춤형 대책을 제시하거나 분석을 통해 보안 요구사항을 도출하였다. 하지만 연구과정에서 APT life cycle 관점이 반영되지 않으면, 지능형 지속 위협인 APT를 인지 및 대응하기 어려운 문제점이 있다. 이러한 문제점을 해결하기 위해, 본 논문은 APT 시나리오 기반의 위협 모델링 분석을 통해 슈퍼컴퓨터 보안 요구사항을 도출 한다.

• Journal of Venture Innovation
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• v.6 no.4
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• pp.1-21
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• 2023

This study is related to the performance of open innovation collaboration between startups and large corporations and financial institutions. In the life cycle of a typical company, the growth of a startup is difficult to predict. Startups that possess innovative technology but have only recently been established seek to verify their technology and capabilities by participating in open innovation with large corporations and financial institutions, and further strive to lay the foundation for corporate growth. However, if you approach it only as a theoretical coexistence plan, it will be viewed as a vague attempt from the startup's perspective. The purpose of this study is to differentiately verify the benefits of open innovation by analyzing the difference in sales growth of startups for the purpose of sales performance based on the open innovation participation of large companies and small and medium-sized companies(startups). In verifying this, the analysis was based on the sales results of the actual open innovation collaboration B2C model, and the difference was confirmed by comparing before and after collaboration. Here, the differentiation of the study was added by reflecting the corporate growth stage theory, a growth theory. When the corporate growth stage theory was excluded, it was confirmed that sales growth due to open innovation of startups was applied from the third month, and sales growth depending on participation was confirmed to be significant. On the other hand, when the corporate growth stage theory was applied, sales growth was not significant, but the difference in growth could be confirmed from the fourth month, and it was also confirmed in sales growth depending on participation. As a result, this study objectively confirms the effects that can be gained when startups participate in Open-innovation, and it is expected that Open-innovation led by large corporations, financial institutions, and government agencies will develop into a high-quality program environment.

• Journal of Family Resource Management and Policy Review
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• v.27 no.3
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• pp.21-37
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• 2023

This study examines the living conditions and life satisfaction of single-person households according to their life cycle. The survey was conducted from August to October 2022, and respondents were single-person households from Kimpo, South Korea. The respondents were categorized to three groups namely, young, middle-aged, and older adults by life cycle, and items regarding their sociodemographic background, personal life, family relations, and life satisfaction were included in the analysis. Descriptive statistics, Chi-square analysis, analysis of variance, and multiple regression analysis were performed. The key findings were as follows. First, significant differences were found according to life cycle in the respondents' diet, clothing, housing, financial and home management, self-care, and leisure life. Second, the variables that significantly affected the level of life satisfaction of single-person households were the life cycle with young adults showing a higher level of satisfaction; having a family member to care; living alone voluntarily, discrimination experience; community awareness; and ties with the local community. Based on the results, it is clear that single-person households have different needs and problems in each stage of life cycle. Thus, to reflect the different experiences and needs of single-person households by life cycle, tailored policy and programs should be provided for young, middle-aged, and older adult single-person households.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.302-309
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• 2016

Urea-SCR system is currently regarded as promising NOx reduction technology for diesel engines. SCR system has to achieve maximal NOx conversion in combination with minimal $NH_3$ slip. In this study, model based open loop control for urea injection was developed and assessed in the European Transient Cycle (ETC) for heavy duty diesel engine. On the basis of the transient modeling, the kinetic parameters of the $NH_3$ adsorption and desorption are calibrated with the experimental results performed over the zeolite based catalyst. $NH_3$ storage or surface coverage of SCR catalyst can not be measured directly and has to be calculated, which is taken into account as a control parameter in this model. In order to reduce $NH_3$ slip while maintaining NOx reduction, $NH_3$ storage control algorithm was applied to correct the basic urea quantity. If the actual $NH_3$ surface coverage is higher than the maximal $NH_3$ surface coverage, the urea injection quantity is significantly reduced in the ETC cycle. By applying this logic, the resulting $NH_3$ slip peak can be avoided effectively. With optimizing the kinetic parameters based on standard SCR reaction, it suggests that a simplified, less accurate model can be effective to evaluate the capability of model based control in the ETC cycle.

• The Journal of Korean Academic Society of Nursing Education
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• v.18 no.3
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• pp.436-445
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• 2012

Purpose: The purpose of this study was to identify social support networks for each life-cycle stage of adults. Method: A total of 1,047 subjects included 454 young adults, 262 middle-aged adults and 331 senior adults. Data were collected using Oh's Korean Version Norbeck's Social Support Questionnaire (NSSQ), and analyzed using descriptive statistics, t-test, and ANOVA. Result: For the young adults, parents were the top and second priority as important social support resources, the third was siblings, and then friends. For the middle-aged, spouse was the first priority as an important social support resource, while the second and the third were children. For the senior adults, children ranked from the top to the seventh priority. The mean number of social support resources was 13.23 for the young adult, 12.93 for the middle-aged and 5.30 for the senior adults. Social support networks of the young adults significantly differed according to gender and marital status. That of the middle-aged significantly differed according to family size. In addition, that of the senior adults was significantly different according to marital status, economic status, religion and family size. Conclusion: It is essential to consider social support networks for each life-cycle stage of adults when making a social support intervention program.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.45-50
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• 2013

Closed-loop J-T (Joule-Thomson) refrigeration cycle is advantageous compared to common open loop $N_2$ decompression system in terms of nitrogen consumption. In this study, two closed-loop pure $N_2$ J-T refrigeration systems with sub-atmospheric device for cooling High Temperature Superconductor (HTS) power cable are investigated. J-T cooling systems include 2-stage compressor, 2-stage precooling cycle, J-T valve and a cold compressor or an auxiliary vacuum pump at the room temperature. The cold compressor and the vacuum pump are installed after the J-T valve to create sub-atmospheric condition. The temperature of 67 K is possible by lowering the pressure up to 24 kPa at the cold part. The optimized hydrocarbon mixed refrigerant (MR) J-T system is applied for precooling stage. The cold head of precooling MR J-T have the temperature from 120 K to 150 K. The various characteristics of cold compressor are invstigated and applied to design parameter of the cold compressor. The Carnot efficiency of cold compressor system is calculated as 16.7% and that of vacuum pump system as 16.4%. The efficiency difference between the cold compressor system and the vacuum pump system is due to difference of enthalpy change at cryogenic temperature, enthalpy change at room temperature and different work load at the pre-cooling cycle. The efficiency of neon-nitrogen MR J-T system is also presented for comparison with the sub-atmospheric devices. These systems have several pros and cons in comparison to typical MR J-T systems such as vacuum line maintainability, system's COP and etc. In this paper, the detailed design of the subcooled $N_2$ J-T systems are examined and some practical issues of the sub-atmospheric devices are discussed.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.125-130
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• 2018

The technology development of a high performance upper stage engine for a GEO(GEostationary Orbit) KSLV(Korea Space Launch Vehicle) is undergoing in Korea Aerospace Research Institute. KSLV is composed of an open cycle engine with gas generator, which is for a low orbit launch vehicle. However the future GEO launch vehicle requires a high performance upper stage engine with a high specific impulse. The staged combustion cycle engine is necessary for this mission. In this paper, current progress and future plan for staged combustion cycle engine development is described.