• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2307-2316
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• 2024

A melting failure of W monoblock components of the upper divertor outer target in EAST occurred during the plasma campaigns in 2019. The failure characters and microstructure evolution of the failed W monoblock have been well investigated on one string (W436 string). Near the strike point region where heat flux density is highest, macroscopic cracks and severe surface damage such as dimensional change, melting and solidification are visible in several W monoblocks. At the same time, debonding, melting and migration of Cu/CuCrZr cooling tube components introduced fatal damage to the structure and function. The heat-induced microstructure evolution in the rest part has been examined via hardness tests and metallography. From the heat flux surface to the cooling tube, hardness increased gradually and the recrystallized grains could be found in the region with the highest temperature, while recrystallization grains also appear in some W monoblocks near the cooling tube area. The detailed microstructure has been investigated by metallography and EBSD. Such cases in EAST provide experiences on the extreme condition of accidental loss of coolant or higher discharge power in future devices.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1501-1512
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• 2024

Plasma disruption in tokamak experiments is a challenging issue that causes damage to the device. Reliable prediction methods are needed, but the lack of full understanding of plasma disruption limits the effectiveness of physics-driven methods. Data-driven methods based on supervised learning are commonly used, and they rely on labelled training data. However, manual labelling of disruption precursors is a time-consuming and challenging task, as some precursors are difficult to accurately identify. The mainstream labelling methods assume that the precursor onset occurs at a fixed time before disruption, which leads to mislabeled samples and suboptimal prediction performance. In this paper, we present disruption prediction methods based on anomaly detection to address these issues, demonstrating good prediction performance on J-TEXT and EAST. By evaluating precursor onset times using different anomaly detection algorithms, it is found that labelling methods can be improved since the onset times of different shots are not necessarily the same. The study optimizes precursor labelling using the onset times inferred by the anomaly detection predictor and test the optimized labels on supervised learning disruption predictors. The results on J-TEXT and EAST show that the models trained on the optimized labels outperform those trained on fixed onset time labels.

• Journal of architectural history
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• v.15 no.3
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• pp.43-57
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• 2006

The Villa Mairea (1937-39) designed by Alvar Aalto (1898-1976) has been studied by many researchers from various viewpoints. However, few studies have devoted their attention to the major issue raised by Aalto at the Yale University lecture and "Mairea" article in arkitekten in 1939. The issue is to fuse art with life in the living room with mobile partition walls that can function both as art exhibition walls and as art storage cabinets at the same time. Through this device, he maintained, the client can change displayed pictures easily according to the situation and so "painting and everyday life can evolve in a more direct manner." This paper argues that Aalto's concept originated from Japanese 'tokonoma' in Tetsuro Yoshida's Das japanische Wohnhaus (1935), which he referred to during the project. Differently from other Japanese features in the house, this tokonoma idea is more than formal, but more decisive than passing in driving the plan. And, whether coincidently or not, his idea exactly corresponds to Japanese aesthetes' and critics' own interpretation of the tononoma as the symbolic centre of Japanese people's everyday life. More importantly, however, this art display concept discloses secret strata of modern architecture during the time when the petrified rationalism was still at its power Even through the tokonoma motif alone, we see diverse trails in modern architecture: fusion of the East and the West, fusion of the traditional and the modern, to say nothing of fusion of art with life.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.465-471
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• 2018

Recently, biometric technology has begun to be used as a fusion of IT technology and financial system. Using this biometric technology, FIDO(Fast Identity Online) technology, Samsung and Apple started Samsung Pay and Apple Pay service. FIDO authentication technology replaces existing authentication methods such as passwords. Among the biometric technologies, fingerprint recognition technology is attracting attention because it can minimize the device and user rejection at a relatively low price. However, fingerprint information has a limited number of users and it can not be reused if fingerprint information is leaked by an external attacker. Therefore, in this paper, we propose a method to authenticate a user using EEG signal which is one of biometrics technologies. W propose a method to use EEG signal measurement value in FIDO system by using convenience channel by using short channel EEG device. And propose a method to utilize EEG signal when the user recognizes a specific entity by measuring the EEG signal before and after recognizing a specific entity.