• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.158-175
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• 2005

Statement of problem. Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however desired level of development has not to be made in this field yet. Purpose. This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of flxed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows : Results. 1. Length of service of fixed restorations serviced in Korea was 6.86$\pm$0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51$\pm$0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21$\pm$0.66) and that of the teen age group(3.39$\pm$0.28) was shortest (p<0.05). 4. Longevity of fixed restorations of women (7.38$\pm$0.18 years) was longer than that of men (6.00$\pm$0.26) (p<0.05). 5. As for the provider factor (such as unlicensed performers, university hospitals, and private clinic), there was no statistically significant difference in longevity of fixed restorations. 6. Defective margin (34.78%). periodontal disease (12.15%), periapical involvement (11.73%), was the most frequent causes of failure and poor esthetics group showed the longest life above all (p<0.05). Actual frequent causes of failure after removing old prosthetics were defective margin, periapical involvement, periodontal disease and uncemented restoration. In 75.67% of the cases, abutment state after removing old prosthetics was good enough for loading another prosthetics. 7. There was found to have statistically significant influence between longevity of single crown (6.35$\pm$0.20 yr) and that of 3 unit fixed restorations (7.60$\pm$0.30 y) (p<0.05). In each case the most frequent cause of failure was defective margin. 8. The number of cantilever pontic, pontic/abutment ratio, oral hygiene status were found to have no statistically significant influence on longevity of fixed restorations in all groups (p>0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60$\pm$0.40 yr) semi precious and precious trailing behind(p<0.05). 10. Group function group (37.04%) and partial group function group (44.62%) were predominant in frequency but showed no correlation between them and among different types of occlusal plane and different types of occlusal surface (p>0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35$\pm$0.62) (p<0.05) among different types of occlusal interference. Conclusion. We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of axed restorations, unified research design. overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.41-46
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• 1986

Exogenous factor and nutrients affecting for conidial germination of Colletetrichum dematium f. sp. capsicum causing red pepper anthracnose were studied by slide germination test. Optimum temperature of conidial germination was at $28^{\circ}C$, ranging 15 to $35^{\circ}C$. Optimum pH was at 5.5, ranging 4.5 to 8.0, and more than 90% of relative humidity (RH) was optimum. Poor conidial germination of the fungus was observed on sterile distilled water, but potato sucrose broth (PSB), red pepper fruit broth (RPFB), green pepper fruit broth (GPFB) and pepper leaf broth (PLB) furnished a satisfactory nutrients for conidial germination. Exogenous supply of carbon and nitrogen sources were essential for conidial germination, while potassium, phosphorous and sulfur were not evident as that for carbon and nitrogen. Soluble starch was the most suitable as a carbon source for conidial germination and followed by D-glucose, D-galactose and lactose in that order. Maximum germination was attained in the $1{\times}10^4$ conidia per ml. Germination was decreased with increment of conidial concentration, and in the density of $5{\times}10^4$ conida per ml, germination was nearly supipressed. It suggested existing a self-inhibitor. Non-washed conidia germinated more than washed conidia, and conidial germination was also gradually decreased by increasing conidial density.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11a
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• pp.29-30
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• 2002

The goal of this research was to develop the effectiveness of in vitro culture method for A. formosanus and study the environment in vitro conditions affecting on growth. The first series of experiments were examined to investigate the response of three different basal media, MS (Murashige and Skoog, 1962), Knudson (KC; Knudson, 1946) and modified hyponex on growth and multiplication during in vitro culture. Multiple shoot proliferation was induced in shoot tip explants on Hyponex (H3) media supplemented with BA (1 mg1$\^$-1/) or TDZ (1-2 mg1$\^$-1/). Addition of activated charcoal (1%) to the TDZ containing medium promoted rapid shoot tip proliferation (11.1 shoots per explant) but the same medium had an opposite effect resulting in poor proliferation in the nodal explants. However, the regenerated shoots had slow growth rate and failed to elongate. This problem was overcome by transferring the shoot clumps to a hormone free H3 media supplemented with 2% sucrose and 0.5% activated charcoal. Using bioreactor culture for scaling up was also shown the best way for multiple shoot induction and growth of this plant. The second series of experiments was studied to investigate the effect of physical environment factors on growth of in vitro plantlets. The Anoectochilus formosanus plantlets were cultured under different air exchange rate (0.1, 0.9, 1.2h$\^$-1/), without sucrose or supplement 20g.1$\^$-1/ (photoautotrophic or photomixotrophic, respectively), and different photosynthesis photon flux (40, 80, 120 ,${\mu}$mol.m$^2$.s$\^$-1/- PPF). Under non-enrichment CO$_2$ treatment, slow growth was observed in photoautotrophical condition as compared with photomixotrophical condition on shoot height, fresh weigh and dry weight parameters; High air exchange (1.2.h-l) was found to be inadequate for plant growth in photomixotrophical condition. On the contrary, under CO$_2$, enrichment treatment, the plant growth parameters were sharply (visibly) improved on photoautotrophic treatments, especially on the treatment with air exchange rate of 0.9.h-1. The growth of plant in photoautotrophic condition was not inferior compared with photomixotrophic, and the best growth of plantlet was observed in treatment with low air exchange rate (0.9.h-1). Raising the PPF level from 80 to 120${\mu}$mol.m$\^$-2/.s$\^$-1/ decreased the plant height, particularly at 120${\mu}$mol.m$\^$-2/.s$\^$-1/ in photoautotrophic condition, fresh weight and dry weight declined noticeably. At the PPF of 120${\mu}$mol.m$\^$-2/,s$\^$-1/, chlorophyll contents lowed compared to those grown under low PPF but time courses of net photosynthesis rate was decreased noticeably. Light quality mainly affected morphological variables, changes of light quality also positively affected biomass production via changes in leaf area, stem elongation, chlorophyll content. Plant biomass was reduced when A. formosanus were grown under red LEDs in the absence of blue wavelengths compare to plants grown under supplemental blue light or under fluorescent light. Stem elongation was observed under red and blue light in the present experiment. Smaller leaf area has found under blue light than with other lighting treatments. Chlorophyll degradation was more pronounced in red and blue light compared with white light or red plus blue light which consequent affected the photosynthetic capacity of the plant. The third series of experiment were studied to investigate the effect of physical environment factors on growth of ex vitro plants including photosynthesis photon flux (PPF), light quality, growing substrates, electrical conductivity (EC) and humidity conditions. In the present experiments, response of plant on PPF and light quality was similar in vitro plants under photosynthesis photon flux 40${\mu}$mol.m,$\^$-2/.s$\^$-1/ and white light or blue plus red lights were the best growth. Substrates testing results were indicated cocopeat or peat moss were good substrates for A. formosanus growth under the greenhouse conditions. In case of A. formosanus plants, EC is generally maintained in the range 0.7 to 1.5 dS.m-1 was shown best results in growth of this plant. Keeping high humidity over 70% under low radiation enhanced growth rate and mass production.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.677-682
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• 1993

Background: Massive hemoptysis is a major clinical problem with high mortality. Bronchial artery embolization is well accepted and widely used for treatment of massive and recurrent hemoptysis, especially in patients with chronic diffuse pulmonary disease who are poor candidates for surgery. We evaluated the therapeutic effect of transcatheter arterial embolization for immediate control and prevention of recurrent hemoptysis. Method: We reviewed 20 cases(M:F=13:7) of bronchial artery embolization for the management of massive hemoptysis from Jun 1989 to Aug 1992 retrospectively. Results: Underlying causes of hemoptysis were pulmonary tuberculosis(n=14), bronchiectasis(n=3), aspergilloma(n=2) and paragonimiasis(n=1). Embolization material was choosed randomly gelfoam(n=7) or Ivalon(n=11) and in 2 cases both were used simultaneously. Target arteries of embolization were bronchial artery only in 15 cases, non-bronchial systemic arteries with or without bronchial artery in 5 cases. After the arterial embolization, immediate cessation of hemoptysis was achieved in 17 cases(85%) and total recurrence rate including 3 cases of immediate treatment failure was 50%. Among recurrences 3 cases were achieved lobectomy, 1 case was expired by asphyxia due to massive hemoptysis and remained 6 were managed by medical conservative treatment with no further recurrence of hemoptysis during follow up periods. Conclusion: Bronchial artery embolization for treatment of massive or recurrent hemoptysis was effective in immediate bleeding control. Despite high recurrence rate the rebleeding after embolization was less severe and controllable by conservative management. Bronchial artery embolization is valuable as primary trial to massive hemoptysis.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.582-589
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• 2005

Background : The incidence of lung adenocarcinoma, which is more prevalent in women and nonsmokers, is increasing. The aim of this study was to determine the prognostic factors of an adenocarcinoma of the lung. Material and method : The clinical information of patients diagnosed with an adenocarcinoma of the lung at the Kosin University Gospel Hospital from January 1994 to July 2004 was reviewed retrospectively. The survival time of these patients was analyzed by the patient's age, gender, performance status, weight loss, smoking history, location of the primary tumor, clinical stage, serologic tumor markers, and treatment modality. Results : For all 422 patients with an adenocarcinoma of the lung, 247 (58.5%) were male, and their mean age was 59.8 years the. The majority of patients were smokers (58.3%), and the tumors were located in the periphery (59.7%). In the smokers, the tumor was located more in the central airway compared to the non-smokers (42.8% vs. 31.9%, p=0.12). The overall median survival time was 390 days (95% CI;304-436 days). Univariate survival analysis revealed that an older age (${\geq}65$ years old), male, weight loss, smoker, central type, advanced clinical stage, elevated serum carcinoembryonic antigen (CEA, >5 ng/ml) and neuron specific enolase (NSE, >15 ng/ml), and the supportive care only were significantly poor prognostic factors. The median survival time was shorter in the smokers than nonsmokers (289 days vs. 533 days, p<0.001). In addition, it was also shorter in the elevated NSE group than in the normal range group (207 days vs. 469 days, p<0.001). Multivariate analysis showed that age, clinical stage, serum NSE, smoking status, and treatment modality were independent predictors of survival (hazard ratios: 1.68, 1.94, 1.92, 2.39 and 1.57, respectively). Conclusions : Smoking is an important prognostic factor in an adenocarcinoma of the lung, but not gender. This suggests that the better prognosis of women is more related with the lower rate of smoking. In addition, the elevated serum NSE is also an important prognostic in an adenocarcinoma of the lung.

• Asian Journal of Turfgrass Science
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• v.9 no.4
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• pp.293-316
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• 1995

Nitrogen fertilization and cutting practice were studied on turfgrasses and cover plants to investigate the possibility of maintaining green color during the growing season. Research also involved the effect of the nitrogen on a few morphological characteristics of leaf performance elements which might give an information to coloration and life-span of turf leaves. Treatments in the first experiment undertaken on pot included one N level: 350kgN /ha applied as compound fertilizer in split applications of one-half in mid-May and the rest both in late June and August, and four spring-summer cuts: late May, late June, late July and late August. The soil filled in pot a moderately well-drained sandy loam. In the second experiment(field observation) leaf length and width, inflorescence and flowering, and color performance were also investigated. With nitrogen fertilizer applied on turfs, desirable turf color was maintained during a period of poor coloration in specific seasons such as mid-summer for cool season grasses and late fall for warm season grasses comparing to the non-treatment. However, this was not stimulated by cutting treatment to nitrogen status existed. Cutting effect on coloration was more remarkable in both Korean lawngrass and Manilagrass than in cool season turfgrasses such as Italian rye-grass, perennial ryegrass and tall fescue. Especially down-slide of leaf color in cool season turfgrasses could he detected in mid-summer /early fall season ranging up to mid-September. In early November as well as mid-September, Italian ryegrass, perennial ryegrass and tall fes-cue retained a high level of green color as followed by nitrogen application and cutting treatment, and little detectable variation of leaf color notation between cool season turfgrasses was obtained. However, Korean la'vngrass and Manilagrass failed to retain the green color until early November. Color notations in cool season turfgrasses investigated early November on the final date of the experiment ranged from 5 GY 3/1 to 4/8 in 'Ramultra' Italian ryegrass, 'Reveile' perennial ryegrass and 'Arid' tall fescue, but those in Zoysiagrasses were 7.5 YR 4/8 in Korean lawngrass and 2.5 y 5 /6 in Manilagrass. Life-span of leaves was shorter in Italian ryegrass, perennial ryegrass and tall fescue than in beth Korean lawngrass and Manilagrass with and without nitrogen application. In general, leaves appeared in early May had a long life-span than those appeared in late April or mid-June. Nitrogen application significantly prolonged the green color retaining period in perennial ryegrass, Italian ryegrass, Korean lawngrass and Manilagrass, and this was contrasted with the fact that there was no prolonged life-span of leaves emerging in early May and mid-June in tall fescue. SPAD reading values in 48 turfs and cover plants investigated in the field trial were increasing until late June and again decreasing till September. Increasing trends of reading value could be observed in the middle of October in most of grasses. On the other hand, clovers and reed canarygrasses did not restore their color values even in October. Color differences between inter-varieties, and inter-species occurred during the growing season under the field condition implicated that selection of species and /or cultivars for mixture should be taken into consideration. In Munsell color notation investigated in the final date in the middle of November, 32 cultivars belonged under the category of 5 GY and 10 cultivars under the category of 7.5 GY. This was implying that most of cool season turfs and cover plants grown in the center zone of Korean Peninsula which are able to utilize for landscape use can bear their reasonable green color by early or mid-November when properly managed. The applicable possibilities of SPAD readings and Munsell color notation to determine the color status of turfgrasses and cover plants used in this study were discussed.

• Tuberculosis and Respiratory Diseases
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• v.69 no.2
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• pp.95-102
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• 2010

Background: The increasing rate of drug-resistant tuberculosis (TB) is a threat to the public health and TB control. In Korea, about 75~80% of TB patients are treated in private hospitals and the rate has been continuously increasing since 2000. Methods: On a retrospective basis, we enrolled 170 newly diagnosed with or retreated for multidrug-resistant TB (MDR-TB) in 2004 from 21 private hospitals. We extracted the following demographics and treatment history from patient medical records: initial treatment outcomes, cumulative survival rates, treatment outcomes, and prognostic factors. Results: Of the 170 patients, the majority were male (64.1%), the mean age was 44.5 years old, and mean body-mass-index was $20.2kg/m^2$. None of the patients tested positive for HIV. Eleven (6.5%) were confirmed to have extensively drug-resistant TB (XDR-TB) at treatment initiation. Treatment success rates were not different between XDR-TB (36.4%, 4/11) and non-XDR MDR-TB (51.6%, 82/159). Default rate was high, 21.8% (37/170). Far advanced disease on X-ray was a significant negative predictor of treatment success; advanced disease and low BMI were risk factors for all-cause mortality. Conclusion: In private hospitals in Korea, the proportion of XDR-TB in MDR-TB was comparable to previous data. The treatment success rate of MDR-/XDR-TB remains poor and the failure rate was quite high. Adequate TB control policies should be strengthened to prevent the further development and spread of MDR-/XDR-TB in Korea.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.143-151
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• 1999

Purpose: Dermatolymphangioadenitis (DLA) is a common and serious complication of lymphedema which deteriorates lymphatic function. The purpose of this study was to assess the risk of DLA by lymphos-cintigraphy in patients with lower extremity lymphedema. Materials and Methods: The subjects were 59 edematous lower extremities of 50 patients without previous episode of DLA and 12 lower extremities of 6 controls. Whole body images were acquired 1 min and 2 hr after subcutaneous injection of 37 MBq of Tc-99m-antimony sulfide colloid into interdigital spaces of both feet before therapy for lymphedema. The lymphosintigraphic and clinical variables were compared between groups with or without occurrence of DLA during clinical follow up. Results: There were 20 episodes of DLA in 12 extremities during clinical follow-up (19 :6 months). On univariate analysis, there were significant differences in ilioinguinal lymph node uptake, uptake pattern of main lymphatic vessel, clinical stage and therapy compliance between the two groups. After multivariate analysis, only the uptake pattern of main lymphatic vessel and therapy compliance fore confirmed to be independent variables. In other words, non-visualized main lymphatic vessel and poor compliance to therapy were more frequent in extremities with subsequent occurrence of DLA. Conclusion: Lymphoscintigraphy can be used to predict the risk of DLA and may thus be helpful for determining the initial therapeutic plan in patients with lower extremity lymphedema.

• Tuberculosis and Respiratory Diseases
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• v.61 no.1
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• pp.46-53
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• 2006

Background: Intra-abdominal hypertension (IAH) is defined as the presence of either an intra-abdominal pressure (IAP) ${\geq}12mmHg$ or an abdominal perfusion pressure (APP = mean arterial pressure - IAP) ${\leq}60mmHg$. Abdominal compartment syndrome (ACS) is defined as the presence of an IAP ${\geq}20mmHg$ together with organ failure. The purpose of this study was to investigate the prevalence of IAH and ACS on the day of admission and the effects of these maladies on the prognosis of critically ill patients in the ICU. Methods: At the day of admission to the ICU, the IAP was recorded by measuring the intravesicular pressure via a Foley catheter. The APACHE II and III scores were checked and SAPS II was also scored during the days the patients were in the ICU. The primary end point was the prevalence of IAH and ACS at the day of admission and the correlation between them with the 28-days mortality rate. The measurement of IAP continued until the 7th day or the day when the patient was transferred to the general ward before 7th day, unless the patient died or a Foley catheter was removed before 7th day. Patients were observed until death or the 28th day. Results: A total of 111 patients were enrolled. At the day of admission, the prevalence of IAH and ACS were 47.7% and 15.3%, respectively and the mean IAP was $15.1{\pm}8.5mmHg$. The rates of IAH for the survivor and the non-survivor groups were 56.5% and 71.4%, respectively, and these were not significantly different (p=0.593). Yet the rates of ACS between these two groups were significantly different (4/62, 6.5% vs. 13/49, 26.5%; Odds Ratio = 5.24, 95% CI = 1.58-17.30, p=0.004). Conclusion: In the present study, the prevalence of IAH was 47.7% and the prevalence of ACS was 15.3% on the day of admission. ACS was associated with a poor outcome for the critically ill patients in the ICU.

• Journal of Intelligence and Information Systems
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• v.23 no.3
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• pp.139-153
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• 2017

Corporate bankruptcy can cause great losses not only to stakeholders but also to many related sectors in society. Through the economic crises, bankruptcy have increased and bankruptcy prediction models have become more and more important. Therefore, corporate bankruptcy has been regarded as one of the major topics of research in business management. Also, many studies in the industry are in progress and important. Previous studies attempted to utilize various methodologies to improve the bankruptcy prediction accuracy and to resolve the overfitting problem, such as Multivariate Discriminant Analysis (MDA), Generalized Linear Model (GLM). These methods are based on statistics. Recently, researchers have used machine learning methodologies such as Support Vector Machine (SVM), Artificial Neural Network (ANN). Furthermore, fuzzy theory and genetic algorithms were used. Because of this change, many of bankruptcy models are developed. Also, performance has been improved. In general, the company's financial and accounting information will change over time. Likewise, the market situation also changes, so there are many difficulties in predicting bankruptcy only with information at a certain point in time. However, even though traditional research has problems that don't take into account the time effect, dynamic model has not been studied much. When we ignore the time effect, we get the biased results. So the static model may not be suitable for predicting bankruptcy. Thus, using the dynamic model, there is a possibility that bankruptcy prediction model is improved. In this paper, we propose RNN (Recurrent Neural Network) which is one of the deep learning methodologies. The RNN learns time series data and the performance is known to be good. Prior to experiment, we selected non-financial firms listed on the KOSPI, KOSDAQ and KONEX markets from 2010 to 2016 for the estimation of the bankruptcy prediction model and the comparison of forecasting performance. In order to prevent a mistake of predicting bankruptcy by using the financial information already reflected in the deterioration of the financial condition of the company, the financial information was collected with a lag of two years, and the default period was defined from January to December of the year. Then we defined the bankruptcy. The bankruptcy we defined is the abolition of the listing due to sluggish earnings. We confirmed abolition of the list at KIND that is corporate stock information website. Then we selected variables at previous papers. The first set of variables are Z-score variables. These variables have become traditional variables in predicting bankruptcy. The second set of variables are dynamic variable set. Finally we selected 240 normal companies and 226 bankrupt companies at the first variable set. Likewise, we selected 229 normal companies and 226 bankrupt companies at the second variable set. We created a model that reflects dynamic changes in time-series financial data and by comparing the suggested model with the analysis of existing bankruptcy predictive models, we found that the suggested model could help to improve the accuracy of bankruptcy predictions. We used financial data in KIS Value (Financial database) and selected Multivariate Discriminant Analysis (MDA), Generalized Linear Model called logistic regression (GLM), Support Vector Machine (SVM), Artificial Neural Network (ANN) model as benchmark. The result of the experiment proved that RNN's performance was better than comparative model. The accuracy of RNN was high in both sets of variables and the Area Under the Curve (AUC) value was also high. Also when we saw the hit-ratio table, the ratio of RNNs that predicted a poor company to be bankrupt was higher than that of other comparative models. However the limitation of this paper is that an overfitting problem occurs during RNN learning. But we expect to be able to solve the overfitting problem by selecting more learning data and appropriate variables. From these result, it is expected that this research will contribute to the development of a bankruptcy prediction by proposing a new dynamic model.