• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.364-369
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• 1997

It is very difficult to execute the vibration analysis of a huge structure, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.

• Nuclear Engineering and Technology
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• v.36 no.5
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• pp.430-449
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• 2004

A quantitative model for a control system that integrates human operators, systems, and their interactions is developed based on discrete functions. After identifying the major entities and the key factors that are important to each entity in the control system, a quantitative analysis to estimate the recovery failure probability from an abnormal state is performed. A numerical analysis based on assumed values of related variables shows that this model produces reasonable results. The concept of 'relative sensitivity' is introduced to identify the major factors affecting the reliability of the control system. The analysis shows that the hardware factor and the design factor of the instrumentation system have the highest relative sensitivities in this model. T도 probability of human operators performing incorrect actions, along with factors related to human operators, are also found to have high relative sensitivities. This model is applied to an analysis of the TMI-2 nuclear power plant accident and systematically explains how the accident took place.

• Current Optics and Photonics
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• v.5 no.2
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• pp.121-128
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• 2021

We propose a novel, tiny optical receiver engine utilizing an all-in-one package based on embedded optics technology. The package's best transmission S21 and reflection S22 opto-electric (OE) bandwidths are 49.8 GHz and 34.9 GHz, respectively, and the reflectance of the optical engine is below -31.7 dB for all channels. The engine satisfies the MIL-STD-883G standard for reliability tests, such as mechanical and thermal shock, and vibration resistance. The sensitivity after 10 km single-mode fiber (SMF) transmission is below -8 dBm. The optical receiver engine is cost-competitive and applicable for 400G coarse wavelength division multiplexing 4 (CWDM4) 10 km optical transceivers.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.63-67
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• 2021

Isovitexin, a marker compound with various pharmacological activities, in Lespedeza cuneata, was analyzed using high performance liquid chromatography coupled with UV (HPLC/UV). There are no previous reports on using L. cuneata as the source material for the quantification of isovitexin. In this study, we developed an optimized method using HPLC-UV analysis, which was validated using various parameters. Our method demonstrated high specificity, and good separation of the chromatographic peak was achieved. Parameters such as linearity (r2≥0.9997), precision, and accuracy indicated that our proposed analytical method had good reliability and sensitivity. These results demonstrate the utility and convenience of our method for rapidly quantifying isovitexin in L. cuneata extracts.

• Structural Engineering and Mechanics
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• v.83 no.1
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• pp.31-43
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• 2022

A nonlinear gas-spring tuned mass damper is proposed to mitigate the seismic responses of the multi-degree-of-freedom (MDOF) structure, in which the nine-story benchmark model is selected as the controlled object. The nonlinear mechanical properties of the gas-spring are investigated through theoretical analysis and experiments, and the damper's control parameters are designed. The control performance and damping mechanism of the proposed damper attached to the MDOF structure are systematically studied, and its reliability is also explored by parameter sensitivity analysis. The results illustrate that the nonlinear gas-spring TMD can transfer the primary structure's vibration energy from the lower to the higher modes, and consume energy through its own relative movement. The proposed damper has excellent "Reconciling Control Performance", which not only has a comparable control effect as the linear TMD, but also has certain advantages in working stroke. Furthermore, the control parameters of the gas-spring TMD can be determined according to the external excitation amplitude and the gas-spring's initial volume.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.19-29
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• 2021

This paper presents the validation of the MCS code for critical safety analysis with burnup credit for the spent fuel casks. The validation process in this work considers five critical benchmark problem sets, which consist of total 80 critical experiments having MOX fuels from the International Criticality Safety Benchmark Evaluation Project (ICSBEP). The similarity analysis with the use of sensitivity and uncertainty tool TSUNAMI in SCALE was used to determine the applicable benchmark experiments corresponding to each spent fuel cask model and then the Upper Safety Limits (USLs) except for the isotopic validation were evaluated following the guidance from NUREG/CR-6698. The validation process in this work was also performed with the MCNP6 for comparison with the results using MCS calculations. The results of this work showed the consistence between MCS and MCNP6 for the MOX fueled criticality benchmarks, thus proving the reliability of the MCS calculations.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.1-10
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• 2022

This paper reviews the principles, advantages, and disadvantages of main explosives detection technologies, as well as research areas needed in the future. Explosives detection technology can be classified into spectroscopic methods, sensor techniques, and olfactory type sensors. There have been advances in explosives detection technology, however studies on discriminatory, portability, and sensitivity for explosives detection still remained competitive.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.289-303
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• 2022

This article examines the multidimensional index extraction method of the disability social security system based on data mining. While creating the data warehouse of the social security system for the disabled, we need to know the elements of the social security indicators for the disabled. In this context, a clustering algorithm was used to extract the indicators of the social security system for the disabled by investigating the historical dimension of social security for the disabled. The simulation results show that the index extraction method has high coverage, sensitivity and reliability. In this paper, a multidimensional extraction method is introduced to extract the indicators of the social security system for the disabled based on data mining. The simulation experiments show that the method presented in this paper is more reliable, and the indicators of social security system for the disabled extracted are more effective in practical application.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.616-617
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• 2015

Demand is increasing for large, high-rise, and complex buildings, which is leading to advances in the development of high-performance structural systems. In this context, precast concrete (PC) technology has received a large amount of attention owing to its benefits in terms of schedule reduction, high quality, and easy installation. In addition, advanced methodologies that improve the PC performance by the addition of various materials have recently been reported. Research on analyzing the effects of such high-performance PC on the construction process and productivity is very limited. This makes it difficult for decision-makers to apply PC to particular projects. Thus, the aim of this research was to analyze the work productivity of the high-performance PC slab installation process by using a construction simulation tool to resolve critical issues. In this study, a real construction project that adopted PC slab installation work was analyzed, and a sensitivity analysis was performed to confirm the reliability of the analysis results.

• Current Optics and Photonics
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• v.8 no.4
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• pp.327-344
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• 2024

Optical phantoms are essential in optical imaging and measurement instruments for performance evaluation, calibration, and quality control. They enable precise measurement of image resolution, accuracy, sensitivity, and contrast, which are crucial for both research and clinical diagnostics. This paper reviews the recent advancements and challenges in phantoms for optical coherence tomography, photoacoustic imaging, digital holographic microscopy, optical diffraction tomography, and oximetry tools. We explore the fundamental principles of each technology, the key factors in phantom development, and the evaluation criteria. Additionally, we discuss the application of phantoms used for enhancing optical-image quality. This investigation includes the development of realistic biological and clinical tissue-mimicking phantoms, emphasizing their role in improving the accuracy and reliability of optical imaging and measurement instruments in biomedical and clinical research.