• Korean Journal of Radiology
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• 제23권4호
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• pp.446-454
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• 2022

Objective: To evaluate whether hyperoxia-induced ΔR₁ (hyperO₂ΔR₁) can accurately identify histological infarction in an acute cerebral stroke model. Materials and Methods: In 18 rats, MRI parameters, including hyperO₂ΔR₁, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and ¹⁸F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and nonischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO₂ΔR₁ and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO₂ΔR₁-derived infarction and histological cell death was evaluated. Results: HyperO₂ΔR₁ increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO₂ΔR₁ sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO₂ΔR₁ value of 0.04 s^-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO₂ΔR₁ higher than 0.04 s^-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). Conclusion: HyperO₂ΔR₁ may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.

• 통상정보연구
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• 제3권1호
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• pp.139-155
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• 2001

The managing strategies of each enterprise has been fundamentally changed due to the emergence of digital economics by using the internet. Therefore it is indispensable for each enterprise to be changed their business strategies. With a view to meeting the change of new economic paradigm, they are efforting to build a infrastructure for information and communication, induce foreign capital, reconsider their conditions of location, draw the law concerned and reinforce education for experts etc. In consideration of these change, the KwangYang port have to introduce e-Business for the purpose of increasing the level of their competition. We - our government, the companies - concerned with port management should recognize and use efficiently our core competence and potentiality of our port management. To achieve it, firstly port industries are to handle not only international logistic system but also communication, finance and sightseeing. Secondly, the developed off-line system have to be harmonizing with the on-line. Therefore, this paper are focused to suggest the theoretic background by analyzing the strategic points of e-port which are divided in 6C - Contents, Community, Connection, Commerce, Communication and Customization.

• 무역상무연구
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• 제16권
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• pp.205-244
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• 2001

The managing strategies of each enterprise has been fundamentally changed due to the emergence of digital economics by using the internet. Therefore it is indispensable for each enterprise to be changed their business strategies. With a view to meeting the change of new economic paradigm, they are efforting to build a infrastructure for information and communication, induce foreign capital, reconsider their conditions of location, draw the law concerned and reinforce education for experts etc. In consideration of these change, the Pusan port & the KwangYang port have to introduce e-Business for the purpose of increasing the level of their competition. We - our government, the companies - concerned with port management should recognize and use efficiently our core competence and potentiality of our port management. To achieve it, firstly port industries are to handle not only international logistic system but also communication, finance and sightseeing. Secondly, the developed off-line system have to be harmonizing with the on-line. Therefore, this paper are focused to suggest the theoretic background by analyzing the strategic points of e-port which are divided in 6C - Contents, Community, Connection, Commerce, Communication and Customization.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3128-3149
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• 2018

A number of effective methods for multiple-attribute group decision making (MAGDM) with interval-valued intuitionistic fuzzy numbers (IVIFNs) have been proposed in recent years. However, the different methods frequently yield different, even sometimes contradictory, results for the same problem. In this paper a novel criterion to determine the advantages and disadvantages of different methods is proposed. First, the decision-making process is divided into three parts: translation of experts' preferences, aggregation of experts' opinions, and comparison of the alternatives. Experts' preferences aggregation is considered the core step, and the quality of the collective matrix is considered the most important evaluation index for the aggregation methods. Then, methods to calculate the similarity measure, correlation, correlation coefficient, and energy of the intuitionistic fuzzy matrices are proposed, which are employed to evaluate the collective matrix. Thus, the optimal method can be selected by comparing the collective matrices when all the methods yield different results. Finally, a novel approach for aggregating experts' preferences with IVIFN is presented. In this approach, experts' preferences are mapped as points into two-dimensional planes, with the plant growth simulation algorithm (PGSA) being employed to calculate the optimal rally points, which are inversely mapped to IVIFNs to establish the collective matrix. In the study, four different methods are used to address one example problem to illustrate the feasibility and effectiveness of the proposed approach.

• 한국문헌정보학회지
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• 제32권3호
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• pp.127-142
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• 1998

본 연구는 국내연구자들이 학술정보의 습득을 위해 국내학술지를 어느정도로 활용하는가를 계열별로 비교분석한 것이다. 그리하여 그 결과를 오늘날 각 대학에서 진행되고 있는 학술지평가 작업의 기초자료로 활용하기 위함이 목적이다. 연구를 위한 조사의 진행은 박사학위논문과 대표 학회지를 대상으로 인용분석을 실시하였으며 학술지평가에 적용할 만한 결과를 얻었다. 먼저, 국내학술지에 대한 의존도에 있어서는 학문계열간에 구별될 만한 차이가 있음으로써 학술지평가 과정에서 학문계열간에 서로 다른 기준의 적용이 필요함을 알았다. 그리고 학술지 활용순위의 등간분석을 통해서는 $50\%$ 이하의 지배력을 갖는 상위학술지에 대해서는 핵심학술지를 선별하기 위한 적절한 보완되는 기준을 마련해야 한다는 것도 알았다.

• 산업경영시스템학회지
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• 제44권3호
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• pp.125-132
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• 2021

In this study, the improvement of the IP system, which is the core infrastructure of the MRO project, and its effect were analyzed. Systematic problems and problems that are not competitive in the actual operating environment were systematically derived, and based on this, the most suitable method for target system development was found and improved. And the data of the improved system was analyzed and the effect was verified through empirical analysis of the system improvement effect through the user questionnaire. As a result of the study, the item with the highest improvement effect was convenience, which increased by 12.43 points. Then it increased by 10.25 points in terms of features. In particular, you will notice a significant improvement in speed by 30-50%. This is because the empirical analysis results are more objective and realistic than other conceptual models. Also, from the practical point of view, based on the results of the empirical analysis, corporate management can more effectively promote the intellectual property system, which is expected to contribute to the enhancement of corporate competitiveness.

• 드라이브 ㆍ 컨트롤
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• 제18권2호
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• pp.20-31
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• 2021

An excavator is a construction machine that can perform various tasks such as trenching, piping, excavating, slope cutting, grading, and rock demolishing. In the 2010s, unmanned construction equipment using ICT technology was continuously developed. In this paper, the path design process was studied to implement the output data of the decision stage, and the path design algorithm was developed. For example, the output data of the decision stage were terrain data around the excavator, excavator mechanism information, excavator hydraulic information, the position and posture of the bucket at key points, the speed of the desired bucket path, and the required excavation volume. The result of the path design was the movement of the hydraulic cylinder, boom arm, bucket, and bucket edge. The core functions of the path design algorithm are the function of avoiding impact during the excavation process, the function to calculate the excavation depth that satisfies the required excavation volume, and the function that allows the bucket to pass through the main points of the excavation process while maintaining the speed of the desired path. In particular, in the process of developing the last function, the node tracking method expressed in the path design table was newly developed. The path design algorithm was verified as this path design satisfied the JCMAS H02 requirement.

• 방사성폐기물학회지
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• 제19권4호
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• pp.447-457
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• 2021

Graphite Isotope Ratio Method (GIRM) can be used to estimate plutonium production in a graphite-moderated reactor. This study presents verification results for the GIRM combined with a 3-D polynomial regression function to estimate cumulative plutonium production in a graphite-moderated reactor. Using the 3-D Monte-Carlo method, verification was done by comparing the cumulative plutonium production with the GIRM. The GIRM can estimate plutonium production for specific sampling points using a function that is based on an isotope ratio of impurity elements. In this study, the ¹⁰B/¹¹B isotope ratio was chosen and calculated for sampling points. Then, 3-D polynomial regression was used to derive a function that represents a whole core cumulative plutonium production map. To verify the accuracy of the GIRM with polynomial regression, the reference value of plutonium production was calculated using a Monte-Carlo code, MCS, up to 4250 days of depletion. Moreover, the amount of plutonium produced in certain axial layers and fuel pins at 1250, 2250, and 3250 days of depletion was obtained and used for additional verification. As a result, the difference in the total cumulative plutonium production based on the MCS and GIRM results was found below 3.1% with regard to the root mean square (RMS) error.

• 국제교류와 융합교육
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• 제2권2호
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• pp.1-8
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• 2022

In March 2021, the <Guidance on Promoting the Scientific Interface between Kindergarten and Elementary School> issued by the Ministry of Education of China clearly pointed out that it is necessary to adhere to child oriented. This goal of this policy is based on the idea of "living education" proposed by Mr. Heqin Chen in 1940, which indicates that a true understanding of children is necessary before talking about educating them. The core goal of "bidirectional articulation" is to strengthen the sense of articulation between kindergartens and elementary school, scientifically prepare for and adapt to school enrollment, and promote the smooth transition of children. Moreover, the <Guidance Points for Kindergarten Readiness Education> and the <Guidance Points for Elementary School Adaptation Education>, which were released at the same time as the <Guidance on Promoting the Scientific Interface between Kindergarten and Elementary School>, also place special emphasis on the cultivation of children's life preparation and adaptability. The aim of the bidirectional articulation "bridging" is to realize a two-way exchange of curriculum between kindergarten and elementary school, and to reform the curriculum at three levels through the curriculum spirit of "gamification", the continuous curriculum structure, and the developmental curriculum evaluation.

• Steel and Composite Structures
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• 제50권1호
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• pp.89-105
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• 2024

Multichannel analysis of surface waves (MASW) method has exhibited broad application prospects in the nondestructive detection of interfacial debonding in steel-concrete composite structures (SCCS). However, due to the structural diversity of SCCS and the high stealthiness of interfacial debonding defects, the feasibility of MASW method needs to be investigated in depth. In this study, synthetic parametric study on MASW nondestructive debonding detection for SCCSs is performed. The aim is to quantitatively analyze influential factors with respect to structural composition of SCCS and MASW measurement mode. First, stress wave composition and propagation process in SCCS are studied utilizing 2D numerical simulation. For structural composition in SCCS, the thickness variation of steel plate, concrete core, and debonding defects are discussed. To determine the most appropriate sensor arrangement for MASW measurement, the effects of spacing and number of observation points, along with distances between excitation points, nearest boundary, as well as the first observation point, are analyzed individually. The influence of signal type and frequency of transient excitation on dispersion figures from forwarding analysis is studied to determine the most suitable excitation signal. The findings from this study can provide important theoretical guidance for MASW-based interfacial debonding detection for SCCS. Furthermore, they can be instrumental in optimizing both the sensor layout design and signal choice for experimental validation.