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        검색결과 12

        1.
        2023.11 구독 인증기관·개인회원 무료
        When decommissioning of nuclear facilities happens, large amounts of radioactive wastes are released. Because costs of nuclear decommissioning are enormous, effective and economical decontamination technologies are needed to remove radioactive wastes. During NPP operation, corrosion product called Chalk River Unidentified Deposits (CRUD) is generated. CRUD is an accumulation of substances and corrosion products consisting of dissolved ions or solid particles such as Ni, Fe, and Co on the surface of the NPP fuel rod coating. CRUD is slowly eroded by the circulation of hot pressurized water and later deposits on the fuel rod cladding or external housing, thereby reducing heat production by the nuclear fuel. Decontamination of radiologically contaminated metals must be performed before disposal, and several methods for decontaminating CRUD are being studied in many countries. Decontamination technology is an alternative to reducing human body covering and reducing radioactive waste disposal costs, and much research and development has been conducted to date. Currently, the importance of decontamination is emerging as the amount of waste stored in radioactive waste storage is close to saturation, and the amount of radioactive waste generated must be minimized through active decontamination. In this study, a preliminary study was conducted on the removal of CRUD by multiple membrane in an electro-kinetic process using an electrochemicalbased decontamination method. Preliminary research to develop a technology to electrochemically remove CRUD by using a self-produced electrochemical cell to check the pH change over time of the CRUD cell according to voltage, electrolyte, membrane and pH change.
        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 예비 지구과학 교사들이 선다형 문항 제작 실습 프로그램에 참여하는 과정에서 드러나는 문 항 제작 역량의 발달 양상을 이해하는 것이다. 이를 위해 예비 지구과학 교사 15명이 선다형 문항 제작 과정 중 공동 검토 과정에서 나타나는 논의에 초점을 맞춰 그 특징을 분석하였다. 구성주의 근거 이론을 토대로 3단계의 코딩을 수 행한 결과, 36개의 초기 코드, 12개의 초점 코드, 5개의 이론적 코드가 도출되었다. 코딩 범주에 근거하여 논의의 특징 을 규정하는 검토 문화와 문항에 대한 관점을 두 축으로 설정하였으며, 이로부터 수험생의 문제풀이, 조심스레 한 걸음 떼기, 짙어지는 담화를 주제로 하는 세 가지 이야기를 구성하였다. 또한 프로그램 동안 일관되게 드러나는 문항 제작 역량의 한계를 다다르지 못한 노정에 대한 네 번째 이야기로 서술하였다. 문항 제작 과정에서 드러나는 평가 전문성은 예비교사의 정체성 발달과 관련되어 있으며, 본 연구에서 적용한 개발한 프로그램의 효과와 의의 및 프로그램의 개발과 개선을 위한 시사점을 논의하였다.
        5,400원
        4.
        2016.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study is an exploratory case study of writing strategies that Korean EFL graduate students in applied linguistics employed in the semester-long process of L2 computermode research paper writing with the use of multiple resources. Data for writing processes and strategy and resource use were largely collected from a writing strategy inventory questionnaire and writing logs, which were complemented by a keystroke logging program, video recordings and retrospective recall interviews. The results of the study reveal the influence of genre features and variations across writing stages, strategies, resources, and individual writers. Planning was intermingled with researching. The participants deployed certain strategies only at a particular stage or throughout the whole writing process. The students who had higher education in English-speaking countries used fewer strategies and preferred electronic resources to print resources than those who were educated mainly in Korea. The latter also showed a tendency of employing self-regulatory strategies. Findings from the study suggest that the research paper writing process is resourceful, strategic and individually situated, and it involves complex composing behaviors accompanied by more varied strategies and resources than shown in studies of one-time reading-to-write tasks.
        6,400원
        5.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is concerned about the process capability index in single process. Previous process capability indices have been developed for the consistency with the nonconforming rate due to the process target value and skewness. These indices calculate the process capability by measuring one spot in an item. But the only one datum in an item reduces the representativeness of the item. In addition to the lack of representativeness, there are many cases that the uniformity of the item such as flatness of panel is absolutely important. In these cases, we have to measure several spots in an item. Also the nonconforming judgment to an item is mainly due to the range not due to the standard variation or the shift from the specifications. To imply the uniformity concept to the process capability index, we should consider only the variation in an item. It is the within subgroup variation. When the universe is composed of several subgroups, the sample standard deviation is the sum of the within subgroup variation and the between subgroup variation. So the range R which represents only the within subgroup variation is the much better measure than that of the sample standard deviation. In general, a subgroup contains a couple of individual items. But in our cases, a subgroup is an item and R is the difference between the maximum and the minimum among the measured data in an item. Even though our object is a single process index, causing by the subgroups, its analytic structure looks like a system process capability index. In this paper we propose a new process capability index considering the representativeness and uniformity.
        4,000원
        6.
        2015.11 구독 인증기관·개인회원 무료
        막여과 정수처리 공정에서는 효율적 처리와 관리를 위하여, 일정용량의 계열(Train)을 복수로, 고회수율 달성을 위한 다단(Stage)의 구성을 사용한다. 이에 따라, 각 계열 또는 단이 처리해야하는 대상수의 농도가 서로 상이하고, 원수 및 약품의 유입위치와 방향 등에 따라 막오염 특성이 서로 상이하다. 따라서, 본 연구에서는 다수의 계열과 2단으로 구성된 침지식 막여과 정수처리 공정에서 계열 및 단별 오염특성을 파악코자 하였다. 10년 이상 운영이 지속된 막여과 정수처리 공정을 대상으로 한 오염평가실험에서, 전단/앞 계열에서는 무기오염이, 후단/후 계열에서는 유기오염이 상대적으로 높게 나타나는 것을 확인하였으며, 이러한 자료를 바탕으로 막여과공정의 운영관리 방안을 제시할 수 있을 것으로 판단된다.
        7.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we investigate how the power consumption of a heat pump dryer depends on various factors in the drying process by analyzing variables that affect the power consumption. Since there are in general many variables that affect the power consumption, for a feasible analysis, we utilize the principal component analysis to reduce the number of variables (or dimensionality) to two or three. We find that the first component is correlated positively to the entrance temperature of various devices such as compressor, expander, evaporator, and the second, negatively to condenser. We then model the power consumption as a multiple regression with two and/or three transformed variables of the selected principal components. We find that fitted value from the multiple regression explains 80~90% of the observed value of the power consumption. This results can be applied to a more elaborate control of the power consumption in the heat pump dryer.
        4,000원
        8.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Process capability indices (PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process potential and performance. The previous studies have measured only one location on each part in the case of single variate. To
        4,000원
        9.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Ultra-high voltage transformer industry has characteristic of small quantity batch production system by other order processing unlike general mass production systems. In this industry, observance of time deadline is very important in market competitive
        4,000원
        10.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Process Capability indices (PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. In the previous studies, only one design
        4,000원
        11.
        2004.11 구독 인증기관 무료, 개인회원 유료
        Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for multiple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index MCpm using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.
        4,200원
        12.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        Korean agricultural industry has weakened as demand for domestic agricultural products has declined due to accelerating market liberalization, aging and shrinking of rural population, and stagnating rural households’ incomes. On the other hand, as the forth industrial revolution unfolds in earnest, tremendous changes are expected, and those changes won’t be confined to certain industries but would shaken the world we know of entirely. Smart farm, which is one example of the fourth industrial revolution, is increasingly being recognized as a new growth engine for the future as smart farm and the science and technology behind it, not the size of arable land, will determine competitiveness of the agricultural industry and drive agricultural productivity and managerial efficiency. In consideration that John W. Kingdon’s Multiple Streams Framework has recently been presented as an important theoretical model in the policy field, this study analyzed problem stream, policy stream, and political stream in the process of forming the smart farm policy, and looked into what role the government played as policy entrepreneur in policy window. The smart farm policy was put on policy agenda by the government and was approved when the government announced the Smart Farm Plan together with relevant ministries at the 5th Economy-Related Ministers’ Meeting held in April 2018. This suggests that change of the government is the most critical factor in political stream, and explicitly indicates the importance of politics in formation of an agricultural policy. In addition, actual outcome of the policy and how policy alternatives that will enhance people’s understanding will support it seem to be the key to success. It also shows that it is important that policy alternatives be determined based on sufficient discussion amongst stakeholders.