• Journal of Intelligence and Information Systems
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• v.24 no.4
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• pp.1-32
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• 2018

In addition to stakeholders including managers, employees, creditors, and investors of bankrupt companies, corporate defaults have a ripple effect on the local and national economy. Before the Asian financial crisis, the Korean government only analyzed SMEs and tried to improve the forecasting power of a default prediction model, rather than developing various corporate default models. As a result, even large corporations called 'chaebol enterprises' become bankrupt. Even after that, the analysis of past corporate defaults has been focused on specific variables, and when the government restructured immediately after the global financial crisis, they only focused on certain main variables such as 'debt ratio'. A multifaceted study of corporate default prediction models is essential to ensure diverse interests, to avoid situations like the 'Lehman Brothers Case' of the global financial crisis, to avoid total collapse in a single moment. The key variables used in corporate defaults vary over time. This is confirmed by Beaver (1967, 1968) and Altman's (1968) analysis that Deakins'(1972) study shows that the major factors affecting corporate failure have changed. In Grice's (2001) study, the importance of predictive variables was also found through Zmijewski's (1984) and Ohlson's (1980) models. However, the studies that have been carried out in the past use static models. Most of them do not consider the changes that occur in the course of time. Therefore, in order to construct consistent prediction models, it is necessary to compensate the time-dependent bias by means of a time series analysis algorithm reflecting dynamic change. Based on the global financial crisis, which has had a significant impact on Korea, this study is conducted using 10 years of annual corporate data from 2000 to 2009. Data are divided into training data, validation data, and test data respectively, and are divided into 7, 2, and 1 years respectively. In order to construct a consistent bankruptcy model in the flow of time change, we first train a time series deep learning algorithm model using the data before the financial crisis (2000~2006). The parameter tuning of the existing model and the deep learning time series algorithm is conducted with validation data including the financial crisis period (2007~2008). As a result, we construct a model that shows similar pattern to the results of the learning data and shows excellent prediction power. After that, each bankruptcy prediction model is restructured by integrating the learning data and validation data again (2000 ~ 2008), applying the optimal parameters as in the previous validation. Finally, each corporate default prediction model is evaluated and compared using test data (2009) based on the trained models over nine years. Then, the usefulness of the corporate default prediction model based on the deep learning time series algorithm is proved. In addition, by adding the Lasso regression analysis to the existing methods (multiple discriminant analysis, logit model) which select the variables, it is proved that the deep learning time series algorithm model based on the three bundles of variables is useful for robust corporate default prediction. The definition of bankruptcy used is the same as that of Lee (2015). Independent variables include financial information such as financial ratios used in previous studies. Multivariate discriminant analysis, logit model, and Lasso regression model are used to select the optimal variable group. The influence of the Multivariate discriminant analysis model proposed by Altman (1968), the Logit model proposed by Ohlson (1980), the non-time series machine learning algorithms, and the deep learning time series algorithms are compared. In the case of corporate data, there are limitations of 'nonlinear variables', 'multi-collinearity' of variables, and 'lack of data'. While the logit model is nonlinear, the Lasso regression model solves the multi-collinearity problem, and the deep learning time series algorithm using the variable data generation method complements the lack of data. Big Data Technology, a leading technology in the future, is moving from simple human analysis, to automated AI analysis, and finally towards future intertwined AI applications. Although the study of the corporate default prediction model using the time series algorithm is still in its early stages, deep learning algorithm is much faster than regression analysis at corporate default prediction modeling. Also, it is more effective on prediction power. Through the Fourth Industrial Revolution, the current government and other overseas governments are working hard to integrate the system in everyday life of their nation and society. Yet the field of deep learning time series research for the financial industry is still insufficient. This is an initial study on deep learning time series algorithm analysis of corporate defaults. Therefore it is hoped that it will be used as a comparative analysis data for non-specialists who start a study combining financial data and deep learning time series algorithm.

• (The) Research of the performance art and culture
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• no.38
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• pp.349-383
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• 2019

This discussion is focused on Donghaeanbyulsingut's 'gutchum-pan to pray'. 'Gutchum-pan to pray' is repeated in almost all of the geori in Byulsingut, so it is a crucial chum-pan that can never be disregarded in understanding Byulsingutchum. Meanwhile, it supposes that Donghaeanbyulsingut is grounded on the activity of producing 'praying (words) and dance (motions)' within its relationship with the structure of capitalistic society along with the context of traditional rituals. The motion that is newly generated as a response to the concrete expression of 'praying' conducted by a mudang (a shaman), that is, the expression coming from the inside associated with the praying is seen as gutchum. This dance is bound to be in competition and interest among shaman groups, and they tend to influence one another. If praying leads to dance, a mudang can gain profits from capital as well as the value of labor. When the mudang succeeds in forming a bigger bond of sympathy with her praying, the object of praying gets more eager to select byulbi and dances a heoteunchum (impromptu dance) more vigorously. This means that a mudang's ability to perform a ritual is associated with the object of praying's consumption. With his impromptu motions, the object of praying comes to go into 'the field of consumption' within the structure of capitalistic competition before he is aware of it. Behind the communication that praying leads to dance, a lot of things are associated with one another organically. 'Gutchum-pan to pray' is generated by the continuous movement of diversity and unity that the time has within the ritual of the mudang and the object of praying. It continues to create the future 'self' that is different from the present 'self', and it means that he expects variability from the present 'self' through 'gutchum-pan to pray'. The mudang also prays for him arranging the variability of the other (the object of praying) inside her labor. In a big picture, of course, the mudang expects the variability of herself, too, which is connected to the value of her labor. The variability that they expect forms a crucial axis that determines where the flow of time and space that the 'gutchum-pan to pray' has is directed to. The contents of praying are directly related with the villagers' lives, and what leads to dance is mostly related with their jobs. This implies that what the mudang experiences in her everyday consuming activity is directly associated with the villagers' activity for earning money. In other words, the contents of that praying change constantly according to the flow of capitalistic economy. Also, those striving to respond to it before anyone else also expect better life for them by substituting their self to the 'gutchum-pan to pray' eagerly. If so, who are the ones that generate 'gutchum-pan to pray'? This can be understood through relationship among mudangs, relationship between the mudang and villagers, and also relationship among villagers. Their relationships can never be free from the concepts like labor in capitalistic society, consumption and expenditure, or time; therefore, they come to compete with the other, the present self, or the better self within the diverse relationships. This gets to be expressed in any ways, words or motions. And the range that covers the creation of either group or individual 'gutchum-pan to pray' in the village is the village community. Outside the range, it is upsized to the competition of the village unit, so individual praying may become diminished more easily. Although mudangs pray in each geori, it does not mean all praying leads to dance. Within various relationships between mudangs and villagers, 'gutchum-pan to pray' comes to be generated, repeated, and extinct. As it is mitigated to more positive competition, it does not lead to gutchum any longer. In other words, repeating 'gutchum-pan to pray' previously created has turned the object of praying into the state different from the former. Also, the two groups both have experienced the last step of Byulsingut, and at that point, praying does no longer lead to dance. In other words, from the position of the shaman group, it is the finish of their labor time and ritual performance, and from the perspective of the villagers, it means the finish of consuming activity and participation in a ritual. The characteristics of 'gutchum-pan to pray' can be summarized as follows. First, it goes through the following process: competition in the village group → competition in the group → competition among individuals. Second, repeated praying does not lead to 'gutchum'. Third, in the cases of praying for each of the occupation groups, the mudang can induce a bond of sympathy from the objects of praying directly, and this lead to dance. Fourth, the group that fails in being included in the category of praying gets to be alienated from 'gutchum-pan to pray' repeatedly.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.215-228
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• 1999

Background: Sarcoidosis is a chronic granulomatous inflammatory disease of unknown etiology often involving the lungs and intrathoracic lymph nodes. The natural course of sarcoidosis is variable from spontaneous remission to significant morbidity or death. But, the mechanisms causing the variable clinical outcomes or any single parameter to predict the prognosis was not known. In sarcoidosis, the number and the activity of CD4 + lymphocytes are significantly increased at the loci of disease and their oligoclonality suggests that the CD4 + lymphocytes hyperreactivity may be caused by persistent antigenic stimulus. Recently, it has been known that CD4+ lymphocytes can be subdivided into 2 distinct population(Th1 and Th2) defined by the spectrum of cytokines produced by these cells. Th1 cells promote cellular immunity associated with delayed type hypersensitivity reactions by generating IL-2 and IFN-$\gamma$. Th2 cells playa role in allergic responses and immediate hypersensitivity reactions by secreting IL-4, IL-5, and IL-10. CD4+ lymphocytes in pulmonary sarcoidosis were reported to be mainly Th1 cells. IL-12 has been known to play an important role in differentiation of undifferentiated naive T cells to Th1 cells. And, Moller et al. observed increased IL-12 in bronchoalveolar lavage fluid(BALF) in patients with sarcoidosis. So it is possible that the elevated level of IL-12 is necessary for the continuous progression of the disease in active sarcoidosis. This study was performed to test the assumption that IL-12 can be a marker of active pulmonary sarcoidosis. Methods: We measured the concentration of IL-12 in BALF and in conditioned medium of alveolar macrophage(AM) using ELISA(enzyme-linked immunosorbent assay) method in 26 patients with pulmonary sarcoidosis(10 males, 16 females, mean age: $39.8{\pm}2.1$ years) and 11 normal control. Clinically, 14 patients had active sarcoidosis and 12 patients had inactive. Results: Total cells counts, percentage and number of lymhocytes, number of AM and CD4/CD8 lymphocyte ratio in BALF were significantly higher in patients with sarcoidosis than in control group. But none of these parameters could differentiate active sarcoidosis from inactive disease. The concentration of IL-12 in BALF was significantly increased in sarcoidosis patients ($49.3{\pm}9.2$ pg/ml) than in normal control ($2.5{\pm}0.4$ pg/ml) (p<0.001). Moreover it was significantly higher in patients with active sarcoidosis ($70.3{\pm}14.8$ pg/ml) than in inactive disease ($24.8{\pm}3.l$ pg/ml) (p=0.001). Also, the concentration of IL-12 in BALF showed significant correlation with the percentage of AM(p<0.001), percentage(p<0.001) and number of lymphocyte(p<0.001) in BALF, suggesting the close relationship between the level of IL-12 in BALF and the inflammatory cell infiltration in the lungs. Furthermore, we found a significant correlation between the level of IL-12 and the concentration of soluble ICAM-1 : in serum(p<0.001) and BALF (p=0.001), and also between IL-12 level and ICAM-1 expression of AM(p<0.001). The AM from patients with pulmonary sarcoidosis secreted significantly larger amount of IL-12 ($206.2{\pm}61.9$ pg/ml) than those of control ($68.3{\pm}43.7$ pg/ml) (p<0.008), but, there was no difference between inactive and active disease group. Conclusion : Our data suggest that the BALF IL-12 level can be used as a marker of the activity of pulmonary sarcoidosis.