• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.723-730
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• 2019

Acquiring instrumentation signals generated from nuclear power plants (NPPs) is essential to maintain nuclear reactor integrity or to mitigate an abnormal state under normal operating conditions or severe accident circumstances. However, various safety-critical instrumentation signals from NPPs cannot be accurately measured on account of instrument degradation or failure under severe accident circumstances. Reactor vessel (RV) water level, which is an accident monitoring variable directly related to reactor cooling and prevention of core exposure, was predicted by applying a few signals to deep neural networks (DNNs) during severe accidents in NPPs. Signal data were obtained by simulating the postulated loss-of-coolant accidents at hot- and cold-legs, and steam generator tube rupture using modular accident analysis program code as actual NPP accidents rarely happen. To optimize the DNN model for RV water level prediction, a genetic algorithm was used to select the numbers of hidden layers and nodes. The proposed DNN model had a small root mean square error for RV water level prediction, and performed better than the cascaded fuzzy neural network model of the previous study. Consequently, the DNN model is considered to perform well enough to provide supporting information on the RV water level to operators.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.938-946
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• 1996

Hierarchical subband codec has been widely promoted in the field of data compression/decompression because of their simplicity and modular nature. Over the past years, the study has received great attention to the perfect reconstruction (PR)system which perfectly recovers the original input signal at the reconstructed output. However, in the actual subband codec system, the signals that passed through the analysis filter bank are quantized before transmission to the receiver side and reconstructed by the synthesis filter bank. Thus the PR system is impossible and the quantization effects must be carefully considered in the system design such that the system recovers the reconstructed output as possible to the the original input signal with minimum quantization error.In this paper, we propose an optimum hierarchical subband codec structure in the presence of quantizer. The optimality criteria of the code is given to the deign of the hierarchical analysis/synthesis subband filter bank and the quantizer that minimize then output mean square error due to the quantizer in the codec. Specific opti-mum design esamples are shown with level-1, level-2 hierarchical structure. The optimal designs are verified by computer simulation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.6-12
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• 2011

Electric vehicles and robots are real-time distributed control systems composed of multiple drive subsystems using micro controller units. Each control subsystem should be modular, compact, power saving, interoperable and fault tolerable in order to be incorporated into the networked real-time distributed control system. Under the networked real-time distributed control the synchronization problem can be occurred to the position and orientation tracking control due to the load variance, mismatch and time delay between the multiple drive subsystems. This paper suggests two types of position synchronization control of the single link manipulators. One of them is composed of cross controller, Kalman filter and disturbance observer, and the other uses the generation of target trajectories to minimize the gradient vector of the scalar function which is composed of the sum of square errors between the reference input vector and the output vectors. The availability of the proposed control schemes is shown through the control experiments.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.2
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• pp.11-26
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• 2022

The Hallyu wave based on K-pop and K-culture has increased the global interest in Korean culture. Therefore, to satisfy consumer demand, there is an attempt to develop a variable fashion design using traditional Korean culture. Transformable fashion design causes changes in form and meaning according to various situations and needs and can induce active participation of consumers. Therefore, we intend to propose a transformable fashion design that is based on traditional Korean culture but appears in a new form and meets the needs of consumers of fashion design. Among Korean traditional culture, wrapping cloths, bojagi are practically used by ordinary people until now, and their shape and use change according to the user's needs. This study intends to derive expression characteristics by examining the expression tendencies of bojagi and to develop transformable fashion designs through the derived data. The purpose of this study is to make and propose transformable fashion designs in real life using the expression characteristics of Korean bojagi. As the method of this study, we first conducted a literature review. Through this, a case study of empirical production was conducted in parallel with the development and production of transformable fashion designs using bojagi. A total of three illustrations and six variable fashion designs were developed. Two of the six works are transformable fashion design that change through movement and expansion of the square shape, the prototype of the bojagi, and two works are modular, bringing changes in function through combination and separation. The work was produced as a multi-purpose transformable fashion design that can be used as clothes or a bag.