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        검색결과 1,131

        141.
        2022.05 구독 인증기관·개인회원 무료
        Low-and intermediate level waste (LILW) should be solidified and satisfy the waste acceptance criteria (WAC) to be disposed of in the LILW repository. The LILW should be uniformly solidified and should maintain its structural stability under the expected condition according to the WAC. Compressive strength of cement solidified waste should satisfy at least 3.44 MPa to be disposed of in the repository. In addition, its compressive strength should satisfy at least 3.44 MPa after the irradiation, immersion and leaching test. The compressive strength test and dimension of test specimen differ according to countries. However, measured compressive strength of solidified waste is affected by geometry of specimen and test condition. Diameter, ratio between diameter and height, and porosity are one of factors that affect to the compressive strength of cement solidified waste. Generally, specimen with larger diameter shows higher value of measured compressive strength. The ratio of height and diameter shows similar tendency to the diameter while larger porosity generally lowers the compressive strength. In other hands, higher compressive strength is expected when the loading rate is higher during the compressive strength test. U.S. is applying loading rate from ASTM C39 (0.25±0.05 MPa) for the compressive strength test while Korea is applying loading rate from KS F 2405 (0.6 MPa·s−1). France applies loading rate following FT-02-010 (0.5 MPa·s−1) for cement solidified waste. As the measured compressive strength increases when the loading rate increases, the effect of loading rate to the compressive strength of cement solidified waste should be assessed by quantification and consider its effect on the sight of regulation. In this study, the effect of geometric parameters of specimen and test condition to the compressive strength are checked by manufacturing specimen by solidifying mock sludge waste with cement. To prevent increasing amount of secondary waste, effects of ratio of height and diameter and porosity to the compressive strength are checked while diameter value is fixed. For loading rate, loading rate from ASTM C39 and KS F 2405 were compared. Existence of significant variance of measured compressive strengths of cement solidified waste are check by performing statistical analysis. Finally, by analyzing the relationship between test condition and measured compressive strength, the test method that measures the compressive strength conservatively is aimed to be derived.
        142.
        2022.05 구독 인증기관·개인회원 무료
        During the treatment of spent nuclear fuel, radioactive iodine is generated in a liquefied or gaseous form in a specific process. In the case of iodine 129, it is a long-lived nuclide with a very long halflife and has high groundwater mobility under repository conditions. Despite showing a low radioactivity value, research on the management of radioactive iodine from a long-term perspective is continuously being performed. Although research has been conducted using borosilicate glass as a medium for solidifying iodine, compatibility of I in borosilicate glass is very small and the volatility is high in the solidification process. So it is not suitable as a solidified substance of iodine. Therefore, studies on other solidification media to replace them are continuously being conducted. Our research team tried to develop a new medium that can contain iodine in a solidified body stably through a simple heat treatment process and can improve problems such as volatility and waste loading. Iodine is captured as AgI in the Ag ion-exchanged zeolite. So, TeO2, Ag2O, and Bi2O3 having a high AgI loading rate were used as main components. It was named TAB after taking the first letter of each element. In previous studies, the physical properties, structure, and chemical stability of TAB materials were confirmed. PCT (Product Consistent test) was performed to confirm chemical stability. It is mainly used to compare the chemical stability of glass materials with other glass materials, but there are limitations in evaluating the long-term chemical stability of materials. In this experiment, we tried to evaluate the long-term stability of TAB and compare it with borosilicate, which is conventionally used to treat radioactive waste. In addition, we tried to understand the leaching behavior inside the TAB medium. For this purpose, ASTM C1308 test was performed for 365 days, and distilled water and KURT groundwater were used as leachates to examine the effect of ions in the groundwater on the solidified body. To analyze the leaching behavior, ICP-MS and ICP-OES analyses were performed, and the cross-section of the sample after leaching was observed through SEM.
        143.
        2022.05 구독 인증기관·개인회원 무료
        To reduce the environmental burden caused by the disposal of spent nuclear fuel and maximize the utilization of the repository facility, waste burden minimization technology is currently being developed at the Korea Atomic Energy Research Institute (KEARI). The technology includes a nuclide management process that can maximize disposal efficiency by selectively separating and collecting major nuclides in spent nuclear fuel. In addition, for efficient storage facility utilization, the short-term decay heat generated by spent nuclear fuel must be removed from the waste stream. To minimize the short-term thermal load on the repository facility, it is necessary to separate heat generating nuclides such as Cs-137 and Sr-90 from the spent fuel. In particular, Sr-90 must be separated because it generates high heat during the decay process. KAERI has developed a technology for separating Sr nuclides from Group II nuclides separated through the nuclide management process. In this study, we prepared Sr ceramic waste form, SrTiO3, by using the solid-state reaction method for long-term storage for the decay of separated Sr nuclides and evaluated the physicochemical properties of the waste form. Also, the radiological and thermal characteristics of the Sr waste form were evaluated by predicting the composition of Sr nuclides separated through the nuclide management process, and the estimation of centerline temperature was carried out using the experimental thermal data and steady state conduction equation in a long and solid cylinder type waste form. These results provided fundamental data for long-term storage and management of Sr waste.
        144.
        2022.05 구독 인증기관·개인회원 무료
        Deep geologic repositories (DGR) are designed to store spent nuclear fuel and to isolate it from the biosphere for an extended period of time as long as millions of years. The long-term performance of the DGR replies on the performance of the natural geologic barriers after the end of the lifetime for the engineered barrier systems. Typically, multiple analytical and numerical models are used to analyze and ensure the safety of the repositories along both engineered and natural barrier systems. Despite the immense advancement in computing power and modeling techniques over the last few decades, a series of models and their linkage often require many simplifying assumptions in this safety assessment. The degree of the reliability and confidence of the safety analysis is thus highly dependent on the validity of those tools used. Considering the significance of the DGR performance and public attention, the highest level of quality control is necessary for the models employed in the assessment. The performance of the ultimate long-term geologic barrier is determined by the expected travel time of the radioactive species of interest, the level of their dilution or radioactivity at compliance areas, and the uncertainty associated with them. As the species of interest can be carried away from the repository location by groundwater flow, the travel time is determined by groundwater velocity along the flow path from source to biosphere while the dilution is a function of the decay and production rates as well as the diffusion and dispersion. Due to the time scale and the complexity of the physicochemical processes and geologic media involved, the models used for safety evaluation will need to become more and more comprehensive, robust, and efficient which is difficult to achieve in principle. They will also need to be transparent and flexible to satisfy the regulatory quality control requirements. This study thus attempts to develop an accessible, transparent, and extensible integrated hydrologic models (IHM) which can be widely accepted by the regulators as well as scientific community and thus suitable for current and future safety assessment of the DGR systems. The IHM can be considered as a tool and a framework at the same time when it is designed to easily accommodate additional processes and requirements for the future as it is necessary. The IHM is capable of handling the atmospheric, land surface, and subsurface processes for simultaneously analyzing the regional groundwater driving force and deep subsurface flow, and repository scale safety features, providing an ultimate basis for seamless safety assessment in the DGR program. The applicability of the IHM to the DGR safety assessment is demonstrated using simple illustrative examples.
        145.
        2022.05 구독 인증기관·개인회원 무료
        The radioactive waste repository consists of an engineered barrier and a natural barrier and must be managed safely after isolation. We classify the geological events of natural barriers for the evaluation of their present and future disposal stability assessment, they can be divided into regional and regional evolutions according to their scale. Regional evolution can be quantitatively explained by plate tectonics and regional rock distribution, and local evolution can be explained by petrological, mineralogical evidence and ductile, brittle deformation. Plate tectonics can explain the change quantitatively by restoring the direction of the Earth’s magnetic field recorded when rocks were formed. The time units for these changes are tens of millions of years to hundreds of millions of years, but plate tectonic is a way to estimate geological history. It can be assessed by extrapolating past knowledge considering the known geological events of radioactive waste repository. It is possible to derive a conservative value of the change of the geological environment in the time unit of disposal stability. The Korean Peninsula belongs to the edge of the Eurasian plate and is divided into Gyeonggi, Yeongnam Massif, Okcheon orogeny belt, and Gyeongsang Basin. To quantitatively determine their geological history, we collected paleomagnetic data using rocks from the Korea Peninsula (paleomagnetic database and papers). We attempted to carry out the apparent polar wander paths (APWPs) on the Korean Peninsula by collecting and sorting data. Since the Korean Peninsula is composed of multiple massifs, this APWP is expected to serve as a basis for explaining the local crustal rotation or brittle ductile deformation. Furthermore, by extrapolating the change pattern from the past to the present, it can contribute to the estimation of the future geological evolution.
        154.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study deals with replacement analysis of deteriorated equipment for improving productivity of production system. Frequent breakdown of the deteriorated equipment causes a situation that reduces productivity such as low product quality, process delay, and repair cost. However, the replacement of new equipment will be required a high initial investment cost, so it is important to analysis the economic feasibility. Therefore, we analyze the effect of the production system due to the aging effect of the equipment and the feasibility of equipment replacement based on the economic analysis. The process flow, working time, logistics movement, etc. are analyzed in order to build the simulation modeling for a ship and land switchboard production system. Using numerical examples, the economic feasibility analysis of equipment replacement through replacement of existing deteriorated equipment and additional arrangement of new facilities is performed.
        4,000원
        155.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 제도적 이중성(institutional duality)의 관점에서 해외 자회사 자율성의 선행 요인 과 그 성과에 대해 연구하였다. 해외 자회사의 자율성은 자회사가 본사의 영향을 받지 않고 전략적 의사결정을 하고 그 성과에 책임을 질 수 있는 역할을 의미한다. 경영상 본사에서 파생되었으나 물 리적으로 해외에 자리하는 해외 자회사의 자율성에 상반된 영향을 주는 본국과 현지국의 제도적 요 소는 본사의 국제화전략 지향성과 지역 이해관계자 요구이다. 해외 자회사가 직면하게 되는 이러한 상반된 제도적 환경의 자율성에의 효과를 살펴보기 위해, 19개 국가에 진출한 177개 한국기업 해 외 자회사를 대상으로 GLS 분석을 실시하였다. 본사의 국제화전략이 범세계적 통합보다 현지국에 서의 지역별 대응을 지향할수록, 또 지역 이해관계자들의 요구가 강할수록 해외 자회사의 자율성이 높아지는 것으로 분석결과는 나타났다. 해외 자회사들의 자율성이 높을수록 자회사는 해당 지역 이 해관계자 들과의 긴밀한 관계를 통해 필요한 자원을 획득하고 본사로부터 제공된 자원과의 적절한 융합을 통해 자회사만의 독특한 경쟁우위를 창출하며 이것이 종국에 기업 성과를 상승시키는 것으 로 분석결과는 보여주고 있다. 또한, 본사의 국제화전략이 현지국에서의 지역별 대응을 지향할수록 자회사 자율성이 자회사 성과에 미치는 긍정적인 영향력을 강화하는 조절 효과가 있는 것으로 나타 나고 있다. 더 나아가, 자회사 자율성은 지역 이해관계자들의 요구가 자회사 성과로 이어지는 데에 부분 매개의 역할을 하는 것으로 확인되었다. 이러한 결과는 다국적 기업의 본사는 해외 자회사의 운영에 있어 지역별 유연성을 발휘할 필요가 있고, 해외 자회사 또한 본사와 현지국 양 편에서 오 는 제도적 압력의 균형점을 찾기 위해 노력할 필요가 있음을 시사한다.
        8,400원
        156.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mutations in the luteinizing hormone/chorionic gonadotropin receptors (LH/CGRs), representatives of the G protein-coupled receptor family, have been rapidly identified over the last 20 years. This review aims to compare and analyze the data reported the activating and inactivating mutations of the LH/CGRs between human, rat, equine and fish, specifically (Japanese eel Anguilla japonica). Insights obtained through detailed study of these naturally-occurring mutations provide a further update of structure-function relationship of these receptors. Specifically, we present a variety of data on eel LH/CGR. These results provide important information about LH/CGR function in fish and the regulation of mutations of the highly conserved amino acids in glycoprotein hormone receptors.
        4,000원
        157.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        위치 기반 AR 게임에서 모바일 기기의 위치를 정확하게 추정하는 것은 중요한 요소 중 하나이다. 모바일 기 기에 내장되어 있는 위치 추정 시스템이 얼마나 정확하게 위치정보를 추정하는 지가 증강되는 AR 콘텐츠의 정확도를 결정한다. 하지만 도시 환경에서는 건물, 건축물, 광고판, 표지판 등 지형지물 및 장애물에 의해서 위치 추정을 위해 필요한 신호가 반사, 굴절, 회절, 차단 등이 발생하게 되고 그로 인하여 모바일 기기의 위 치 추정 시스템으로부터 추정되는 위치에 오차가 생기게 된다. 본 논문에서는 도시 환경에서 모바일 기기의 위치 오차가 증가하는 현상에 대해서 상용 스트리트 뷰와 문자 태그를 활용하여 심플하면서도 신뢰성 있는 위치 보정 방안을 제안한다. 제안하는 위치 보정 방안은 쿼리 이미지와 스트리트 뷰 파노라마 이미지로부터 생성된 문자 태그를 대조하는 것을 통해서 매칭 스코어를 계산한고 매칭 스코어에 따라 쿼리 이미지를 촬영 한 실제 위치와 가까운 스트리트 뷰를 검색하는 것을 통해서 모바일 기기의 위치를 보정한다. 제안하는 위치 보정 방안은 위치 오차가 43.71m인 위치를 위치 오차가 4.09m인 위치로 보정하였으며 낮과 밤에 관계없이 위치를 보정할 수 있다는 장점이 있다.
        4,300원
        158.
        2021.12 구독 인증기관 무료, 개인회원 유료
        With the development of maritime ICT, the introduction of e-navigation and the MASS (maritime autonomous surface ship), the types and scope of maritime communication networks are expanding, and the need for digital AtoN services is increasing. However, due to problems such as the aging of fishing crews, coastal backlight, weather conditions, and inexperience with regard to the use of advanced navigation equipment on board, the visual and electronic perception of AtoN is degraded, and it is difficult to ensure safe ship navigation. In this study, in response to the introduction of the MASS, a plan for the development of an active customized virtual digital AtoN service system in consideration of ship operating conditions and geographic conditions is proposed. The proposed service system may facilitate electronic identification of AtoN and contribute to preventing marine accidents by ensuring the safe navigation of ships.
        4,000원
        159.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the era of the 4th industrial revolution driven by the convergence of ICT(information and communication technology) and manufacturing, research on smart factories is being actively conducted. In particular, the manufacturing industry prefers smart factories that autonomously connect and analyze data. For the efficient implementation of smart factories, it is essential to have an integrated production system that vertically integrates separately operated production equipment and heterogeneous S/W systems such as ERP, MES. In addition, it is necessary to double-verify production data by using automatic data collection technology so that the production process can be traced transparently. In this study, we want to show a case of data-centered integration of a large aircraft parts processing factory that requires high precision, takes a long time, and has the characteristics of processing large raw materials. For this, the components of the data-oriented integrated production system were identified and the connection structure between them was explained. And we would like to share the experience gained through the design and implementation case. The integrated production system proposed in this study integrates internal components based on data, which is expected to serve as a basis for SMEs to develop into an advanced stage, and traces materials with RFID technology.
        4,300원
        160.
        2021.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이번 연구는 남원식 추어탕의 주재료인 추어와 무청시래기에 대한 인식개선과 이를 이용하여 젊은 연령층의 기호도에 적합한 분쇄육 제품을 개발하고자 추진되었다. 떡갈비 주원료인 돈육과 우지의 15%를 추어 페이스트로 대체 한 추어 떡갈비를 대조구로 사용하였으며, 대파의 일정비율(25%, 50%, 75%, 100%)을 무청시래기로 대체하여 추어와 무청시래기가 첨가된 떡갈비 시료를 제조하였다. 무청 시래기를 첨가한 떡갈비는 가열·조리 후 pH와 당도는 각각 6.07-6.28과 9.94-10.9로 시중에서 유통되는 떡갈비의 개별 특성에 적합하였다. 가열·조리에 따른 가열감량은 대파를 사용한 대조구에 비하여 대파를 무청시래기로 대체한 떡갈비 시료에서 유의적으로 낮았지만 무청시래기의 첨가량에 따른 유의적인 차이는 없었다. 가열 전과 가열·조리 후 무청시래기를 첨가한 떡갈비의 수분함량은 모두 대조구 보다 높았으며 이는 무청시래기의 식이섬유가 육가공품의 보수성을 높여 가열감량을 감소시킨 것으로 판단되었다. 대파를 무청시래기로 대체한 떡갈비 시료의 명도(44.5- 47.8)는 시료 간의 유의적인 차이를 보이지 않은 반면 적색도(0.77-4.97)와 황색도(6.92-12.8)는 무청시래기의 첨가량에 따라 유의적으로 감소하였다. 떡갈비 시료에 대한 TPA 결과, 부착성은 대파를 무청시래기로 대체한 떡갈비 시료에서 대조구보다 유의적으로 낮아졌으나 경도, 응집성, 검성, 씹힘성에서는 대조구와 무청시래기를 첨가한 시료 간에 유의적인 차이를 확인할 수 없었다. 무청시래기가 첨가된 떡갈비 시료에 대한 관능적인 평가에서 색, 연도, 다즙성에서 대조구보다 낮은 점수를 받았다. 전반적인 기호도 역시 무청시래기가 첨가되지 않은 대조구에서 가장 높은 점수를 받았으나 무청시래기를 첨가한 시료에서는 대파의 50%를 대체한 시료에서 높은 점수를 받았다. 무청시래기 자체가 지닌 특유의 향미는 관능적인 평가에서 확인되지 않았으며 전자코를 이용한 향기패턴 분석에서도 낮은 분별 지수(-90)로 시료 간의 향기패턴 차이를 확인하기 어려운 수준이었다. 이번 연구를 통해 떡갈비의 제조에서 대파를 대체하는 무청시래기의 함량은 25-50%가 적절하였으며 무 청시래기와 추어가 지닌 특유의 맛과 냄새로 인한 영향을 받지 않는 떡갈비를 개발함으로써 향후 남원지역의 향토음식과 연계되는 새로운 메뉴개발이 가능하게 되었다.
        4,000원