• MALSORI
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• no.33_34
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• pp.127-136
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• 1997

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.347-353
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• 2019

The composition of the reduced fuel produced in the electrolytic reduction process of pyroprocessing affects the concentration change of $UCl_3$, an important operating variable of the electrorefining process. In this study, we examined the concentration change of $UCl_3$ in the electrorefiner according to the content of TRU and RE elements in the reduced fuel and the concentration of $Li_2O$ introduced in the electrorefiner accompanied with the reduced fuel. Considering only the TRU and RE elements, the concentration of $UCl_3$ decreased with increasing the number of electrorefining operation batch. In order to operate one campaign (20 batches) of electrorefining process, it was found that additional injection of $UCl_3$ should be conducted more than 3 times. On the other hand, the concentration of $UCl_3$ in the electrorefiner changed significantly depending on the concentration of $Li_2O$ and, accordingly the number of operable electrorefining batches decreased rapidly, showing that the concentration of $Li_2O$ is an important operating variable in electrorefining. Therefore, the results of this study show that to maintain the concentration of $UCl_3$ in the electrorefiner, the operation mode should be set by taking into account the effect of $Li_2O$ as well as the TRU and RE elements contained in the reduced fuel.

• International Journal of Oral Biology
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• v.47 no.3
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• pp.41-48
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• 2022

Ulva compressa Linnaeus (UCL) is a green algae seaweed that performs photosynthesis and is used as a food material in some Asian regions including Korea. It is known to be the dominant species in copper ion-contaminated seas, and many studies on copper ion resistant mechanisms have been reported. UCL is known to have an excellent antioxidant effect, but limited information is available regarding its other physiological activities. In this study, we investigated the anticancer activity of 30% prethanol extracts of Ulva compressa Linnaeus (30% PeUCL) and the underlying mechanisms of its activity on human FaDu hypopharyngeal squamous carcinoma cells. The 30% PeUCL extracts suppressed FaDu cell viability without affecting normal cells (L929), as determined by MTT and viability assays. Furthermore, the 30% PeUCL extracts induced apoptosis, as determined by DAPI staining. The 30% PeUCL extracts inhibited colony formation effectively as well as wound-healing of FaDu cells, even at noncytotoxic concentrations. In addition, 30% PeUCL extracts induced apoptosis significantly through proteolytic cleavage of caspase-3, -7, and -9, and poly (ADP-ribose) polymerase, and by downregulation of Bcl-2 and upregulation of Bax in FaDu cells, as determined by Western blot analysis. Collectively, these results suggest that the inhibitory effect of 30% PeUCL extracts on the growth of oral cancer cells, colony formation and wound-healing may be mediated by caspase- and mitochondrial-dependent apoptotic pathways in human FaDu hypopharyngeal squamous carcinoma cells. Therefore, 30% PeUCL extracts can be administered as a natural chemotherapeutic drug for the treatment of human oral cancers.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.207-215
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• 2020

The feasibility of rare earth (RE) removal process via oxidation reactions with UCl₃ was investigated using the HSC Chemistry code to reduce the concentrations of RE in transuranic (TRU) products. The composition and thermodynamic data of TRU and RE elements contained in the reference spent fuel were examined. The reactivity was evaluated by calculating equilibrium data considering oxidation reactions with UCl₃. Both RE removal rate and TRU recovery rate were evaluated for the two cases, wherein TRU products with different RE concentrations were used. When TRU products were reacted with UCl₃, selective oxidation was driven by the difference in the Gibbs free energy of each element. The calculation results imply that the TRU/RE ratio of the final product can be increased by removing RE elements while maintaining the maximum recovery rate of TRU, which is accomplished by controlling the amount of UCl₃ injected. Since the results of this study are based on thermodynamic equilibrium data, there are many limitations to apply to the actual process. However, it is expected to be used as an important data for the process design to supply the TRU product of pyroprocessing to SFR's fuel demanding low RE concentrations.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.1
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• pp.59-64
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• 2018

In case of high contents of rare earths in the LiCl-KCl salt, it is not easy to recover U and TRU metals as a usable resource form from LiCl-KCl eutectic salts generated from the pyroprocessing of spent nuclear fuel. In this study, a conversion of $UCl_3$ into an oxide form using $K_2CO_3$ and an electrodeposition of $NdCl_3$ into a metal form in $LiCl-KCl-UCl_3-NdCl_3$ system were conducted to resolve the problem. Before conducting the conversion, experimental conditions for the conversion were determined by performing a thermodynamic equilibrium calculation. In this study, almost all of $UCl_3$ disappeared in the LiCl-KCl salt when the injection of $K_2CO_3$ reached theoretical equivalent for the conversion, and then $NdCl_3$ was effectively electrodeposited as a metal form using liquid zinc cathode. After that, the LiCl-KCl salt became transparent, and uranium oxides were precipitated to the bottom of the LiCl-KCl salt. These results will be utilized in designing a process to separate U and rare earths in LiCl-KCl salt.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.102-102
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• 2011

• 한국IT서비스학회:학술대회논문집
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• 2007.05a
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• pp.385-390
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• 2007

유비쿼터스 서비스는 운전자, 헬스케어 관련 종사자, 일반 시민 등 모바일 사용자를 위한 서비스를 포괄하고 있다. 이러한 서비스들은 단말 장치로부터 발생하는 다양한 정보들을 수집, 가공하여 개인들에게 제공할 수 있도록 한다. 최근에 진행되고 있는 u-City 에서는 건강과 교육, 가정 환경에서 일어나는 다양한 이벤트들을 기반으로 상황에 따라 개인화된 서비스를 거주지, 거리, 빌딩, 공공 장소 같은 다양한 환경에 제공하려 하고 있다. 최근의 표준화 논의에서는 다양한 공공 서비스와 상용/민간 서비스를 지원하기 위해 공유할 수 있는 단말, 네트워크, 센터, 소프트웨어 인프라스트럭처가 필요하다는 공감대가 형성되어 표준화 논의가 활성화되고 있다. 본 논문에서 소개하는 TOPAZ는 서비스 기반의 유비쿼터스 컴퓨팅 인프라스트럭처로 다양한 유비쿼터스 서비스들이 웹 서비스를 통해 인프라스트럭처를 사용하여 쉽게 개발, 배포, 운용될 수 있게 해준다. 본 논문에서는 TOPAZ의 필요성과 서비스 컴포넌트들에 대해 서술하고 유틸리티 컴퓨팅의 입장에서 본 서비스의 질, 서비스 미터링, 자원 관리, Scalability 등의 고려 사항과 해결 방법을 제시하고 TOPAZ의 성능, 적용 결과 등을 소개한다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2015.10a
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• pp.87-88
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• 2015

• Journal of IKEEE
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• v.25 no.4
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• pp.598-606
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• 2021

In this paper, we presents a new service binding and resource management model for context based services in mobile edge computing (MEC) networks. The proposed control is composed of two layers: MEC service bindng control layer (MCL) and user context control layer (UCL). The MCL manages service binding construction, resource allocation, and service policy construction from a system point of view; and the UCL manages real-time service adaptation using meta-objects. Through simulations, we confirmed that the proposed control offers enhanced throughput and content transfer time when it is compared to the legacy computing and control models. The proposed control model can be employed as a key component for the context based various internet-of-things (IoT) services in MEC environments.

• Journal for History of Mathematics
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• v.24 no.3
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• pp.109-143
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• 2011

Augustus De Morgan became to be deeply interested in the education of pure mathematics since he came to teach in UCL because of the specific nature of natural philosophy lectures, the academical knowledge and reasoning powers of the students, and the negative attitudes of London society on mathematics. During his long tenure, he really tried his best to make his students understand the important concepts and the principles of pure mathematics, and logically explain the processes of inducing and proving the laws of pure mathematics. When he could not stay as a mere researcher, he had to concern himself with and pay attention to the problems of educating students. And then his teaching style was constructed in a specific way by the various attitudes about mathematics, the boundary relationship between the adjacent academical branches, and the social and systematic nature of UCL.