• East Asian mathematical journal
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• v.37 no.1
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• pp.79-85
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• 2021

In this paper, we investigate the valuation of vulnerable exchange option that has credit risk of option issuer. The reduced-form model is used to model credit risk. We assume that credit event is determined by the jump of the counting process with stochastic intensity, which follows the mean reverting process. We propose a simple approach to derive the closed-form pricing formula of vulnerable exchange option under the reduced-form model and provide the pricing formula as the standard normal cumulative function.

• Korean Institute of Interior Design Journal
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• v.13 no.3
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• pp.35-42
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• 2004

This study dealt with approaches in architecture and music in the contemporary situation characterized by accidence and uncertainty through Pierre Boulez and Rem Koolhaas' works. First of all, we examined basic positions with starting from zero degree breaking from fixed ideas and with relative neutrality. Then, from a methodological aspect, we inquired into 1) anti-hierarchical objective approach, 2) accidental approach to form. 3) diagram of structure and event, and 4) the use of selective routes. Lastly, from a receptive aspect, we dealt with the space of pluralistic perspective and works in progress. The two persons used chaosmos approach that enables adjustment and control through structure defining the relationship with accidence or chaos. With the approach, they created works in progress or open works that have a pluralistic viewpoint working in the field of specific relation and the concept of endless regeneration.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.357-368
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• 2015

People observe lots of events around the environment and we can easily recognize the nature of an event from the resulting optic flow. The questions are how do people recognize events and what is the information in the optic flow that enables observers to recognize events. Motor theorists claim that human observers exhibit special sensitivity when perceiving events like speech or biological motion, because we both produce and perceive those events. However, direct perception theorists suggested that speech or biological motion is not special from the perception of all other kinds of event. The purpose of this review article is to address this controversy to critique the motor theory and to describe a direct realist approach to event perception. It is important to understand the fundamental information of how human perceive event perception for the convergence on robotics.

• Management & Information Systems Review
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• v.28 no.1
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• pp.25-44
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• 2009

This study examines long term performance of initial public offerings(IPO) after book building was introduced in KOSDAQ market. We use event time portfolio approach and calendar time portfolio approach to test if the performance of IPO is fair or not in long term. We estimate the performance by using the BHAR(buy and hold abnormal return), CAR(cumulative abnormal return), WR(wealth relatives) model in event time portfolio approach. And we calculate the performance by using Fama-French three factor model, CTAR(calendar time abnormal return), RATS(Return Across Time and Securities approach) model in calendar time portfolio approach. This study shows that the long term performance of IPO is positive with statistical significance as the results of the analysis through the various research method and all windows in all kinds of firms and total firms.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.96.1-96
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• 2002

$\textbullet$ Abstract $\textbullet$ Introduction $\textbullet$ Building a Model for Diagnosis $\textbullet$ Modular Approach to Diagnosis $\textbullet$ Extension to a General Case $\textbullet$ Conclusion $\textbullet$ References

• Journal of Biomedical Engineering Research
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• v.33 no.1
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• pp.15-24
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• 2012

Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (${\pm}9.64%$) was attained for the proposed method; whereas an average accuracy of 57% (${\pm}5.68%$) was attained for the conventional method (significance was assessed by the one-tail paired $t$-test, $p$ < 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.492-500
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• 2003

By means of the transformation from the problem of fuzzy reliability to the problem of general reliability, a model for analyzing fuzzy reliability is introduced in this paper Because of the complexity of the Problem of the fuzzy reliability, generally speaking, the analytical equations for calculating fuzzy reliability indexes of machine part cannot be obtained in most cases. Therefore, in this paper, an approach is given wherein progressions are employed to calculate them, or a simulation approach is used to estimate them by expressing general reliability indexes as progressions. By utilizing the approach put forwards in the paper, the calculating quantity for analyzing the fuzzy reliability will be reduced : even substantially reduced sometimes. Some examples are taken to explain the feasibility of the model and a simulation approach.

• Journal of the Korean Society of Safety
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• v.36 no.5
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• pp.86-91
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• 2021

Calculating the scrutable core damage frequency (CDF) of nuclear power plants is an important component of the seismic probabilistic safety assessment (SPSA). In this work, a simple approach is developed to calculate CDF from minimal cut sets (MCSs) with non-rare events. When conventional calculation methods based on rare event approximations are employed, the CDF of industry SPSA models is significantly overestimated by non-rare events in the MCSs. Recently, quantification algorithms using binary decision diagrams (BDDs) have been introduced to prevent CDF overestimation in the SPSA. However, BDD structures are generated from a small part of whole MCSs due to limited computational memory, and they cannot be reviewed due to their complicated logic structure. This study suggests a simple approach for scrutinizing the CDF calculation based on whole MCSs in the SPSA system analysis model. The proposed approach compares the new results to outputs from existing algorithms, which helps in avoiding CDF overestimation.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1372-1386
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• 2018

Despite recent advances in multi-hazard analysis, the complexity and inherent nature of such problems make quantification of the landslide effect in a probabilistic safety assessment (PSA) of NPPs challenging. Therefore, in this paper, a practical approach was presented for performing an earthquake-induced landslide PSA for NPPs subject to seismic hazard. To demonstrate the effectiveness of the proposed approach, it was applied to Korean typical NPP in Korea as a numerical example. The assessment result revealed the quantitative probabilistic effects of peripheral slope failure and subsequent run-out effect on the risk of core damage frequency (CDF) of a NPP during the earthquake event. Parametric studies were conducted to demonstrate how parameters for slope, and physical relation between the slope and NPP, changed the CDF risk of the NPP. Finally, based on these results, the effective strategies were suggested to mitigate the CDF risk to the NPP resulting from the vulnerabilities inherent in adjacent slopes. The proposed approach can be expected to provide an effective framework for performing the earthquake-induced landslide PSA and decision support to increase NPP safety.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.43-48
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• 2017

Movie ratings are crucial for recommendation engines that track the behavior of all users and utilize the information to suggest items the users might like. It is intuitively appealing that information about the viewing preferences in terms of movie genres is sufficient for predicting a genre of an unlabeled movie. In order to predict movie genres, we treat ratings as a feature vector, apply a Bernoulli event model to estimate the likelihood of a movie being assigned a certain genre, and evaluate the posterior probability of the genre of a given movie by using the Bayes rule. The goal of the proposed technique is to efficiently use movie ratings for the task of predicting movie genres. In our approach, we attempted to answer the question: "Given the set of users who watched a movie, is it possible to predict the genre of a movie on the basis of its ratings?" The simulation results with MovieLens 1M data demonstrated the efficiency and accuracy of the proposed technique, achieving an 83.8% prediction rate for exact prediction and 84.8% when including correlated genres.