• Journal of the Korea Society for Simulation
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• v.13 no.4
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• pp.1-16
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• 2004

The modelling and simulation of the activation process for the heart system is meaningful to understand special excitatory and conductive system in the heart and to study cardiac functions because the heart activation conducts through this system. This thesis proposes two dimensional cellular automaton(CA) model for the activation process of the myocardium and conducted simulation by means of discrete time and discrete event algorithm. In the model, cells are classified into anatomically similar characteristic parts of the heart and each of cells has a set of cells with preassigned properties. Each cell in this model has state variables to represent the state of the cell and has some state transition rules to change values of state variables executed by state transition function. The state transition rule is simple as follows. First, the myocardium cell at rest stay in passive state. Second, if any one of neighborhood cell in the myocardium cell is active state then the state is change from passive to active state. Third, if cell's state is an active then automatically go to the refractory state after activation phase. Four, if cell's state is refractory then automatically go to the passive state after refractory phase. These state transition is processed repeatedly in all cells through the termination of simulation.

• Journal of Distribution Science
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• v.21 no.5
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• pp.101-111
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• 2023

Purpose: The purpose of this paper is to examine the effect of the VKOSPI index on short-term stock returns after a large-scale stock price shock of individual stocks of firms in the distribution industry in Korea. Research design, data, and methodology: This study investigates the effect of the change of the VKOSPI index or investor mood on abnormal returns after the event date from January 2004 to July 2022. The significance of the abnormal return, which is obtained by subtracting the rate of return estimated by the market model from the rate of actual return on each trading day after the event date, is determined based on T-test and multifactor regression analysis. Results: In Korea's distribution industry, the simultaneous occurrence of a bad investor mood and a large stock price decline, leads to stock price reversals. Conversely, the simultaneous occurrence of a good investor mood and a large-scale stock price rise leads to stock price drifts. We found that the VKOSPI index has strong explanatory power for these reversals and drifts even after considering both company-specific and event-specific factors. Conclusions: In Korea's distribution industry-related stock market, investors show an asymmetrical behavioral characteristic of overreacting to negative moods and underreacting to positive moods.

• Korean Journal of Radiology
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• v.22 no.10
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• pp.1697-1707
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• 2021

The recent introduction of various high-dimensional modeling methods, such as radiomics and deep learning, has created a much greater diversity in modeling approaches for survival prediction (or, more generally, time-to-event prediction). The newness of the recent modeling approaches and unfamiliarity with the model outputs may confuse some researchers and practitioners about the evaluation of the performance of such models. Methodological literacy to critically appraise the performance evaluation of the models and, ideally, the ability to conduct such an evaluation would be needed for those who want to develop models or apply them in practice. This article intends to provide intuitive, conceptual, and practical explanations of the statistical methods for evaluating the performance of survival prediction models with minimal usage of mathematical descriptions. It covers from conventional to deep learning methods, and emphasis has been placed on recent modeling approaches. This review article includes straightforward explanations of C indices (Harrell's C index, etc.), time-dependent receiver operating characteristic curve analysis, calibration plot, other methods for evaluating the calibration performance, and Brier score.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.4
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• pp.301-306
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• 2007

The people information is distributed in various forms such as database, web page, text, and so on, where the world wide web is one of the main sources of publicly-available people information. It has a characteristic that the information on people is intrinsically temporal. Therefore, the reconstruction of the information is needed for an individual or a company to use it efficiently. In order to maintain or manage the temporal people information, it must distinguish the variable information from invariable information of people. In this paper, we propose a method that constructs an ontology based on events to manage the variable people information efficiently. In addition, we present a system which reconstructs people information that satisfies the users' demand with the ontology.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.20-25
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• 2011

The fire event occurred in fire proof zone often causes serious electrical problems such as shorts, ground faults, or open circuits in nuclear power plants. These would be directed to the loss of safe shutdown capabilities performed by safety related systems and equipments. The fire event can treat the basic design principle that safety systems should keep their functions with redundancy and independency. In case of a multi-core cable fire, operators can not perform their mission properly and can misjudge the situation because of spurious operation, wrong indication or instrument. These would deteriorate the plant capabilities of safety shutdown and make disastrous conditions. In this paper, the characteristic of cable fire is investigated and the heat-flux evaluation for cable fire is studied. Moreover, a diagnostic methodology for degraded cable in nuclear power plants is presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.292-297
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• 2004

This paper is demonstrated about VM that means a circumstance where a application is no dependence of hardware and GVM which is selected by SKT as flatform, thus we developted portris-mobile game based on GVM. this game was embodied(actualized or given to actualized form) by Mobile C and process procedure of Event Drivnen type game that is a characteristic of Mobile C is showed by flowchart.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.3
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• pp.204-211
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• 2011

Embedded systems require intensively complex and high power dissipating modules that have the capability of real-time high performance data processing, wide bandwidth communication, and low power consumption. However, the current battery technology has not been developed as much as meeting the requirements of portable embedded systems for long system lifetime. In this paper, new approach that operates with low energy consumption is proposed to overcome the situation while guaranteeing detection accuracy. The designed method associates a variety of detection algorithms hierarchically to detect events happening around the system. The Change for energy consumption characteristics is shown with change for probabilistic characteristics and those relationships are analytically explained from experiments. Furthermore, several techniques to consume low energy and achieve high detection accuracy are described, depending on the event static or dynamic characteristics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.361.1-361
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• 2002

Coupling adjacent steel frame using elastic dampers fer control of response to low and moderate dynamic event is investigated in this paper. The complex modal superposition method is first used to determine dynamic characteristic, mainly modal damping ratio and modal frequency, of damper linked linear adjacent steel frame for fractical use. Dynamic response of steel frame linked by hydraulic-excitation method. (omitted)

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.1-11
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• 2014

This study aimed at investigating the content and meaning of royal garden(宮苑) sightseeing event in Pyoam Gang, sehwang's "Hogayugeumwongi" As the research method, descriptive research method was used, which is to consider and interpret the content and meaning in the historical records. Research results are summarized as follows. 1. "Hogayugeumwongi", which recorded the event that the King personally guided and explained the palace to the vassals, is a very precious historical records in Korean landscape gardening cultural history. Such thing is unprecedented in Joseon Dynasty as well as China. 2. The person who recorded this event was famous for shi seo hwa samjeol in the time, and the point that he was Pyoam, who was appreciated as 'the head(總帥) of artistic and literary circles(藝苑)', adds more value to the future generations. 3. The characteristic of this sightseeing event was to praise the vassals' labor, who contributed to the completion of Kyujanggak, to establish King Jongjo's direct rule in the early period of seizure of power, and eojin(御眞) dosa(圖寫), etc., which expressed the King's dignity. Jongjo utilized Geumwon, a forbidden place in the palace, to give a special privilege to the vassals' effort, who took a great part in realizing his political ideal. 4. One of sightseeing lines toward the backyard of Changdeok Palace could be identified. Though the sightseeing lines toward the backyard were not fixed, however this might be the best sightseeing line which Jongjo intentionally chose to enjoy that day's flavor of autumn. 5. The characteristic of this event was informal and somewhat extemporary 'sightseeing'. Therefore, it is considered, that day's event was relatively private and free 'play(遊)', while 'sanghwaeojoyeon(賞花漁釣宴)', which Jongjo gave to the vassals middle after his reign, was a royal 'banquet', which prepared frames, such as event holding time and form, qualification for participation, e.g. flower viewing, fishing, writing poems, etc. This research has a significance that it considered the content and meaning in historical records including the front and the rear context that "Hogayugeumwongi" was written through the consideration of related historical materials. "Hogayugeumwongi" can be utilized as a material for storytelling with regard to royal garden sightseeing in future as a valuable cultural content, also, follow-up study on this is necessary.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.805-811
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• 2007

The purpose of this study was to invesitigate relationship between rainfall water quality and precipitation characteristic during the accumulated rainfall and rainless period. As the results of the analysis, rainfall water quality was improved in the rainfall duration. Correlation coefficients between rainwater quality and accumulated rainfall were $0.88{\sim}0.99$ except $Cl^-$. and that between rainless period and initial rainfall water quality were $0.62{\sim}0.75$. During the Asian dust event, concentration of the turbidity, BOD and electric conductivity were high. Therefore, it shows that the rainfall water quality is effected by atmospheric conditions before the rainfall events.