• Smart Structures and Systems
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• v.8 no.3
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• pp.303-320
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• 2011

Comparing to active damage monitoring, impact localization on composite by using time reversal focusing method has several difficulties. First, the transfer function of the actuator-sensor path is difficult to be obtained because of the limitation that no impact experiment is permitted to perform on the real structure and the difficulty to model it because the performance of real aircraft composite is much more complicated comparing to metal structure. Second, the position of impact is unknown and can not be controlled as the excitation signal used in the active monitoring. This makes it not applicable to compare the difference between the excitation and the focused signal. Another difficulty is that impact signal is frequency broadband, giving rise to the difficulty to process virtual synthesis because of the highly dispersion nature of frequency broadband Lamb wave in plate-like structure. Aiming at developing a practical method for on-line localization of impact on aircraft composite structure which can take advantage of time reversal focusing and does not rely on the transfer function, a PZT sensor array based phase synthesis time reversal impact imaging method is proposed. The complex Shannon wavelet transform is presented to extract the frequency narrow-band signals from the impact responded signals of PZT sensors. A phase synthesis process of the frequency narrow-band signals is implemented to search the time reversal focusing position on the structure which represents the impact position. Evaluation experiments on a carbon fiber composite structure show that the proposed method realizes the impact imaging and localization with an error less than 1.5 cm. Discussion of the influence of velocity errors and measurement noise is also given in detail.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.173-178
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• 2016

Background: In situ gamma spectrometry has been used to measure environmental radiation, assumptions are usually made about the depth distribution of the radionuclides of interest in the soil. The main limitation of in situ gamma spectrometry lies in determining the depth distribution of radionuclides. The objective of this study is to develop a method for subsurface characterization by in situ measurement. Materials and Methods: The peak to valley method based on the ratio of counting rate between the photoelectric peak and Compton region was applied to identify the depth distribution. The peak to valley method could be applied to establish the relation between the spectrally derived coefficients (Q) with relaxation mass per unit area (${\beta}$) for various depth distribution in soil. The in situ measurement results were verified by MCNP simulation and calculated correlation equation. In order to compare the depth distributions and contamination levels in decommissioning KRR site, in situ measurement and sampling results were compared. Results and Discussion: The in situ measurement results and MCNP simulation results show a good correlation for laboratory measurement. The simulation relationship between Q and source burial for the source layers have exponential relationship for a variety depth distributions. We applied the peak to valley method to contaminated decommissioning KRR site to determine a depth distribution and initial activity without sampling. The observed results has a good correlation, relative error between in situ measurement with sampling result is around 7% for depth distribution and 4% for initial activity. Conclusion: In this study, the vertical activity distribution and initial activity of $^{137}Cs$ could be identifying directly through in situ measurement. Therefore, the peak to valley method demonstrated good potential for assessment of the residual radioactivity for site remediation in decommissioning and contaminated site.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.117-121
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• 2016

Background: Definition and grouping of initiating events (IEs) are important basics for probabilistic safety assessment (PSA). An IE in a spent fuel reprocessing plant (SFRP) is an event that probably leads to the release of dangerous material to jeopardize workers, public and environment. The main difference between SFRPs and nuclear power plants (NPPs) is that hazard materials spread diffusely in a SFRP and radioactive material is just one kind of hazard material. Materials and Methods: Since the research on IEs for NPPs is in-depth around the world, there are several general methods to identify IEs: reference of lists in existence, review of experience feedback, qualitative analysis method, and deductive analysis method. While failure mode and effect analysis (FMEA) is an important qualitative analysis method, master logic diagram (MLD) method is the deductive analysis method. IE identification in SFRPs should be consulted with the experience of NPPs, however the differences between SFRPs and NPPs should be considered seriously. Results and Discussion: The plutonium uranium reduction extraction (Purex) process is adopted by the technics in a model reprocessing plant. The first extraction cycle (FEC) is the pivotal process in the Purex process. Whether the FEC can function safely and steadily would directly influence the production process of the whole plant-production quality. Important facilities of the FEC are installed in the equipment cells (ECs). In this work, IEs in the FEC process were identified and categorized by FMEA and MLD two methods, based on the fact that ECs are containments in the plant. Conclusion: The results show that only two ECs in the FEC do not need to be concerned particularly with safety problems, and criticality, fire and red oil explosion are IEs which should be emphatically analyzed. The results are accordant with the references.

• Archives of design research
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• v.12 no.1
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• pp.39-48
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• 1999

Industrial design, as a traditional meaning, is based on the method of production by machine beginning with the Industrial Revolution. At present, the identity of design is in confusion with the development of computer and related medium technology. The new wave called 'cyber' has doubts about the hypothesis in the method of production by machine as the production method by machine had doubts about the hypothesis of the production method by handicraft long before. This thesis is a study on how computers and new media, such as virtual reality, change our environments and susceptibilities of life and design culture. The thesis is going to dismantle and reorganize the material-oriented classification based on the production method by machine through the discussion on cyberspace and culture, image. and text, virtual image and reality, and so on. Eventually this study finds out a topography and identity of the design in this changing age.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.249-273
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• 2004

Finding an optimal solution in MADN[(Multi-Attribute Decision-Making) problems is difficult, when the number of alternatives, or that of attributes is relatively large Most of the existing mathematical approaches arrive at a final solution on the basis of many unrealistic assumptions, without reflecting the decision-maker's preference structure exactly. In this paper we suggest a model that helps us find a group consensus without assessing these parameters in specific cardinal values. Therefore, This research provides a comprehensive Decision Making of the theory and methods applicable to the analysis of decisions that involve risk and multiple criteria attributes. after, The emphasis of the procedure will be on developments from the fields of decisions analysis and utility theory of Taguchi Method. This theoretical development will be illustrated through the discussion of several real-world application and a case study. When the multiple number of decision makers are involved in the decision making procedure, the problem of uncertainties invariably occurs, because of the different views between them. In this paper, New decision making model using Taguchi Method is applied to effectively model the multi-attribute-decision making(MADM) procedure in the uncertainties dominated two area(quantitative and qualitative factors), Quantitative factors evaluation is used Loss Function of Taguchi, qualitative factors evaluation is used 50 ratio by each specialist. thus it can be used for aiding of preferable alternative. as a result, We will be proved efficiency about New decision making model of applied Taguchi Method with Analytical presentation of all the expecting outcomes when a specific strategy or an alternative plan is selected under expecting future environment.

• Applied Biological Chemistry
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• v.19 no.3
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• pp.162-171
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• 1976

The determination of rate limiting step in the metabolic process is of great importance to understand the metabolic properties. In this paper the authors propose a modified enzymatic method instead of thermodynamic method. This method is based on the assumption that the over-all rate increment would be larger than by any other steps to which the individual enzyme are added respectively, provided that the enzyme participated in the rate limiting step is added to the reactions composed of n steps of metabolic process with which n kind of enymes are concerned. The present paper deals with analysis and discussion about some factors having influence on the proposed process, mainly about the metabolic process constituted with homogeneous steps. The results show that the determination of rate limiting step by a modified enzymatic method is feasible, provided that some restrictions are added in any type of mechanisms.

• Journal of the Korea Society of Computer and Information
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• v.22 no.6
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• pp.101-107
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• 2017

In this paper, We propose the aesthetic exploration of horseback riding is considered to be the process of pursuing physical, mental, emotional, and social beauty. Despite the search effect of aesthetics in various aspects, the study of equestrian aesthetics in the field of physical education in Korea is very insufficient. Equestrian aesthetics is being studied in the field of special physical education and is being studied in the fields of rehabilitation and therapeutic horseback riding. Horse riding is a type of exercise. However, studies that track and observe various changes are inadequate. The purpose of this study is to explore the theory of equestrian aesthetics and to explore the possibility of approaching aesthetic theory from the top of horseback riding and to extend the area of equestrian game aesthetically. Until now, horse riding has been thought to be an aristocratic sport. Today, however, everyone can participate. Horseback riding is a sport for raising livelihoods, and it is a special sport that animals and humans enjoy in harmony. Equestrianism is a method of aesthetics from below, a philosophical method of aesthetics from the top, and a scientific method of empirical or positivistic direction. This study examines equestrian aesthetics from aesthetic point of view through the whole process of horse riding. The purpose of this study is to explore the aesthetics of horse riding through an aesthetic approach from the top, and to study the nature of aesthetics, a philosophical debate on beauty, Art can be divided into two categories: empiricism and positivism. For the sake of simplicity, the former is called the philosophical method, the latter is called the scientific method, and the latter is called the aesthetic from the bottom. Generally, in art, artistic, artistic works, perfumers, if you are grasped in the triangular shape, equestrian aesthetics can be described as triplets such as horse riding, passengers, and spectators. It was not easy to give satisfactory results in suggesting a new theory or a clear discussion due to lack of precedent research.

• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.53-63
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• 2019

Background: As neutron fields are always accompanied by gamma rays, it is essential to distinguish neutrons from gamma rays in the detection of neutrons. Neutrons and gamma rays can be separated by pulse shape discrimination (PSD) methods. Recently, we performed characterization of a stilbene scintillator detector and an EJ-301 liquid scintillator detector with a high-speed digitizer DT5730 and investigated optimized PSD variables for both detectors. This study is for providing a basis for developing fast neutron/gamma-ray dual-particle imager. Materials and Methods: We conducted PSD experiments using stilbene scintillator and EJ-301 liquid scintillator and evaluated neutron and gamma ray discriminability of each PSD method with a $^{137}Cs$ gamma source and a $^{252}Cf$ neutron source. We implemented digital signal processing techniques to apply two PSD methods - the charge comparison (CC) method and the constant time discrimination (CTD) method - to distinguish neutrons from gamma rays. We tried to find optimized PSD variables giving the best discriminability in a given experimental condition. Results and Discussion: For the stilbene scintillator detector, the charge comparison method and the constant time discrimination method both delivered the PSD FOM values of 1.7. For the EJ-301 liquid scintillator detector, both PSD methods delivered the PSD FOM values of 1.79. With the same PSD variables, PSD performance was excellent in $300{\pm}100keVee$, $500{\pm}100keVee$, and $700{\pm}100keVee$ energy regions. This result shows that we can achieve an effective discrimination of neutrons from gamma rays using these scintillator detector systems. Conclusion: We applied both PSD methods to a stilbene and a liquid scintillator and optimized the PSD performance represented by FOM values. We observed a good separation performance of both scintillators combined with a high-speed digitizer and digital PSD. These results will provide reference values for the dual-particle imager we are developing, which can image both fast neutrons and gamma rays simultaneously.

• The Mathematical Education
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• v.60 no.3
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• pp.321-340
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• 2021

As many changes in the future society represented by the age of artificial intelligence(AI) are expected to come, efforts are being made to draw the shape of the future education and various research methods are being employed to support the attempts. While many research studies use methods for deriving generalized results such as expert survey and trend analysis in along with a review of literature, there are attempts to apply the scenario methodology to explore ideas and information needed within a changing context. A scenario method, one of the experiential learning strategies, aims to seek various and alternative approaches by establishing a plan from the present conditions considering future changes. In this study, in-service teachers' perceptions and expectations of the interactivity between human and AI teachers were visualized by applying the role-play presentation technique that grafted the concept of role-play game to the scenario method. In addition, the mandal-art method was introduced to support in conducting productive discussion during the teachers' collaboration. This method appeared to help to depict teachers' perceptions of AI teachers in the detailed and concrete form, which may flow in the abstract otherwise. Through analyses of the teachers' role-play presentations with the implementation of the madal-art method it was suggested that most teachers would want to collaborate with an AI teacher for improved instruction and individualized student learning while they would take the instructional authority over the AI teacher in the classroom.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.302-315
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• 2020

The issue concerning how to integrate with the needs of sustainable development according to Crime Prevention Through Environmental Design(CPTED) theory still continues in the development process of the third-generation theory at the present stage. In addition, the issue is under worldwide controversy and discussion. What is more noteworthy is that the viewpoints under debate and discussion have an influence on the mutual effect and relationship between the theoretical model and the principles in the theoretical model, and the influence can never be underestimated. After a mastery of the overall context of theoretical development, it is believed in this study that the identity of CPTED theory development can provide a diverse understanding dimension and a communication method between the environment and environmental users. On the basis of identity the development of CPTED theory, the crime prevention design mode of CPTED needs to connect different dimensions of sustainability, with the design goal of livability as the starting point, the Top-down model to adjust the safety of the environment. By no means can the environmental condition be improved by solely relying on the previous physical design method in virtue of Bottom-up model. Therefore, in this study, the identity of CPTED will be set as the core combined with Top-down crime prevention design model to propose a visual proposal for the reconstitution of the theoretical model, rather than supplementing the application of the contents or principles at a certain stage. Hence, it is expected to provide reference and enlightenment for the sustainable development of CPTED theory.