• Journal of Intelligence and Information Systems
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• v.27 no.1
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• pp.103-128
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• 2021

Recently, investors' interest and the influence of stock-related information dissemination are being considered as significant factors that explain stock returns and volume. Besides, companies that develop, distribute, or utilize innovative new technologies such as artificial intelligence have a problem that it is difficult to accurately predict a company's future stock returns and volatility due to macro-environment and market uncertainty. Market uncertainty is recognized as an obstacle to the activation and spread of artificial intelligence technology, so research is needed to mitigate this. Hence, the purpose of this study is to propose a machine learning model that predicts the volatility of a company's stock price by using the internet search volume of artificial intelligence-related technology keywords as a measure of the interest of investors. To this end, for predicting the stock market, we using the VAR(Vector Auto Regression) and deep neural network LSTM (Long Short-Term Memory). And the stock price prediction performance using keyword search volume is compared according to the technology's social acceptance stage. In addition, we also conduct the analysis of sub-technology of artificial intelligence technology to examine the change in the search volume of detailed technology keywords according to the technology acceptance stage and the effect of interest in specific technology on the stock market forecast. To this end, in this study, the words artificial intelligence, deep learning, machine learning were selected as keywords. Next, we investigated how many keywords each week appeared in online documents for five years from January 1, 2015, to December 31, 2019. The stock price and transaction volume data of KOSDAQ listed companies were also collected and used for analysis. As a result, we found that the keyword search volume for artificial intelligence technology increased as the social acceptance of artificial intelligence technology increased. In particular, starting from AlphaGo Shock, the keyword search volume for artificial intelligence itself and detailed technologies such as machine learning and deep learning appeared to increase. Also, the keyword search volume for artificial intelligence technology increases as the social acceptance stage progresses. It showed high accuracy, and it was confirmed that the acceptance stages showing the best prediction performance were different for each keyword. As a result of stock price prediction based on keyword search volume for each social acceptance stage of artificial intelligence technologies classified in this study, the awareness stage's prediction accuracy was found to be the highest. The prediction accuracy was different according to the keywords used in the stock price prediction model for each social acceptance stage. Therefore, when constructing a stock price prediction model using technology keywords, it is necessary to consider social acceptance of the technology and sub-technology classification. The results of this study provide the following implications. First, to predict the return on investment for companies based on innovative technology, it is most important to capture the recognition stage in which public interest rapidly increases in social acceptance of the technology. Second, the change in keyword search volume and the accuracy of the prediction model varies according to the social acceptance of technology should be considered in developing a Decision Support System for investment such as the big data-based Robo-advisor recently introduced by the financial sector.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.339-349
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• 1999

The dental structure substituted by restorative materials may produce discomfort resulting from hot or cold stimuli. To investigate the effects of this stimuli on the human teeth, thermal analysis was carried out by calculation of general heat conduction equation in a modeled tooth using numerical method. The method has been applied to axisymmetric and two-dimensional model, analyzing the effects of constant temperature $4^{\circ}C\;and\;60^{\circ}C$. That thermal shock was provided for 2 seconds and 4 seconds, respectively and recovered to normal condition of $20^{\circ}C$ until 10 seconds. The thermal behavior of tooth covered with a crown of gold or stainless steel was compared with that of tooth without crown. At the same time, the effects of restorative materials(amalgam, gold and zinc oxide-eugenol(ZOE)) on the temperature of PDJ(pulpo-dentinal junction) has been studied. The geometry used for thermal analysis so far has been limited to two-dimensional as well as axisymmetric tooth models. But the general restorative tooth forms a cross shaped cavity which is no longer two-dimensional and axisymmetric. Therefore, in this study, the three-dimensional model was developed to investigate the effect of shape and size of cavity. This three-dimensional model might be used for further research to investigate the effects of restorative materials and cavity design on the thermal behavior of the real shaped tooth. The results were as follows; 1. When cold temperature of $4^{\circ}C$ was applied to the surface of the restored teeth with amalgam for 2 seconds and recovered to ambient temperature of $20^{\circ}C$, the PDJ temperature decreased rapidly to $29^{\circ}C$ until 3 seconds and reached to $25^{\circ}C$ after 9 seconds. This temperature decreased rather slowly with stainless steel crown, but kept similar temperature within $1^{\circ}C$ differences. Using the gold as a restorative material, the PDJ temperature decreased very fast due to the high thermal conductivity and reached near to $25^{\circ}C$ but the temperature after 9 seconds was similar to that in the teeth without crown. The effects of coldness could be attenuated with the ZOE situated under the cavity. The low thermal conductivity caused a delay in temperature decrease and keeps $4^{\circ}C$ higher than the temperature of other conditions after 9 seconds. 2. The elapse time of cold stimuli was increased also until 4 seconds and recovered to $20^{\circ}C$ after 4 seconds to 9 seconds. The temperature after 9 seconds was about $2-3^{\circ}C$ lower than the temperature of 2 seconds stimuli, but in case of gold restoration, the high thermal conductivity of gold caused the minimum temperature of $21^{\circ}C$ after 5 seconds and got warm to $23^{\circ}C$ after 9 seconds. 3. The effects of hot stimuli was also investigated with the temperature of $60^{\circ}C$. For 2 seconds stimuli, the temperature increased to $40^{\circ}C$ from the initial temperature of $35^{\circ}C$ after 3 seconds of stimuli and decreased to $30^{\circ}C$ after 9 seconds in the teeth without crown. This temperature was sensitive to surface temperature in the teeth with gold restoration. It increased rapidly to $41^{\circ}C$ from the initial temperature of $35^{\circ}C$ after 2 seconds and decreased to $28^{\circ}C$ after 9 seconds, which showed $13^{\circ}C$ temperature variations for 9 seconds upon the surface temperature. This temperature variations were only in the range of $5^{\circ}C$ by using ZOE in the bottom of cavity and showed maximum temperature of $37^{\circ}C$ after 3 seconds of stimuli.

• Tuberculosis and Respiratory Diseases
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• v.44 no.5
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• pp.1072-1082
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• 1997

Background : To characterize the clinical features and determine the prognostic factors of severe community-acquired pneumonia. This study is the first of its kind in Korea. Methods : Recruited were 40 patients diagnosed as severe community-acquired pneumonia in Hallym University Hospital from January 1, 1989 through July 31, 1996. Patients were analysed retrospectively for age, sex, underlying disease, respiration rate, hypoxemia, requirement of mechanical ventilation, involvement on chest radiograph, shock, and the serum concentration of BUN and albumin. All parameters were compared between survived and dead group. Results : Male to female ratio was 2.07 : 1. The mean age was $63.1{\pm}17.5$years(range 25~90years) with 65% of patients aged equal to or more than 60. The major underlying diseases were old pulmonary tuberculosis(12.5%), chronic obstructive pulmonary disease(7.5%), bronchial asthma(5%), bronchiectasis(2.5%), and diabetes mellitus(22.5%). Microbiologic diagnosis was made in 26 out of 40 patients(65%). The most common causative organism was S. pneumoniae(17.5%, 7/40) followed by S. aureus(15.0%, 6/40), K. Pneumoniae(12.5%, 5/40), M. tuberculosis(7.5%, 3/40), H. influenzae(2.5%, 1/40), coagulase negative staphylococcus(2.5%, 1/40), P. aeruginosa(2.5%. 1/40), E. cloaceae(2.5%, 1/40), and E. coli(2.5%, 1/40). M. pneumoniae was detected in no patient. The most frequent drugs administered in single or combination therapy were aminoglycosides(75%, 30/40), second- and third-generation cephalosporin(40%, 16/40 and 27.5%, 11/40), macrolides(27.5%, 11/40), and amoxicillin/clavulanic acid(22.5%, 9/40). Of the 40 patients, 14 died of severe community-acquired pneumonia(37.5%). Among them, seven patients (50%) expired within 72h of hospital arrival. According to multivariate analysis, mortality was significantly associated with requirement of mechanical ventilation, bilateral pulmonary involvement, and serum albumins$\leq$3.0g/dl. Conclusion : An understanding of the clinical characteristics and prognostic factors in severe community-acquired pneumonia identified in this study will optimize therapeutic approach in this disease and help decreasing its notorious mortality rate.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.64-75
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• 2005

The total production of food waste was about 11,398ton/day('03) in Korea. Also, food waste was treated by landfill, incineration, reuse and anaerobic digestion. The method of food waste treatment depended primarily on landfill. However, the method of landfill causing social problems was prevented to treat food waste in the first of January 2005.12) Thus, anaerobic digestion is an important method to treat food waste because of possibility of energy recovery as methane gas. In this study, the possibility of food waste treatment containing high organic material and low pH in the one stage anaerobic reactor to save cost and time and energy recovery using $CH_{4}$ gas by the hybrid anaerobic reactor (HAR) was measured. The HAR was designed by combing the merits of the anaerobic filter (AF) to minimize the microorganism shock when food waste of very low pH was injected and up-flow anaerobic sludge blanket (UASB) to prevent from plugging and channeling phenomena by large suspended solids when semi solids were injected. Granule was packed in the section of HAR. The purpose of the BMP experiment was to measure the amount of methane generated when organic material was resolved under anaerobic conditions, to grasp bio resolution of organic material. Total accumulated methane production per VS amount was $0.471(m^{3}/\cal{kg}\;VS)$. So, the value was about $81.2\%$ of theoretical methane production which was $0.58(m^{3}/\cal{kg}\;VS)$ by elementary analysis and organic matter removal velocity (K) was $0.18(d^{-1})$. From these results, food waste was treated by anaerobic treatment. From this study, $CH_{4}$ generation from food waste (11,398 ton/day) could be estimated. By using an energy conversion factor of Braun's study, $5.97KWh/m^{3}\;CH4,\;60\%\;of\;CH_{4}$ gas generation, the amount of total energy producing food waste is to 6,727MWh/day. It could be confirmed that energy recovery using $CH_{4}$ gas was possible. Above these results, food waste containing organic matters of high concentration could be treated in HRT 30 days under an anaerobic condition, using the hybrid anaerobic reactor and reuse of $CH_{4}$ gas was possible.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.113-123
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• 2020

Global climatic change and increasing climatic instability threaten crop productivity. Due to climatic change, drought stress is occurring more frequently in crop fields. In this study, we investigated the effect of treatment with hydrogen peroxide (H₂O₂) before leaf development on the growth and yield of sorghum for minimizing the damage of crops to drought. To assess the effect of H₂O₂ on the growth of sorghum plant, 10 mM H₂O₂ was used to treat sorghum leaves at the 3-leaf stage during growth in field conditions. Plant height, stem diameter, leaf length, and leaf width were increased by 7.6%, 9.6%, 8.3% and 11.5%, respectively. SPAD value, chlorophyll fluorescence (Fv/Fm), photosynthetic rate, stomatal conductance, and transpiration rate were increased by 3.0%, 4.9%, 26.0%, 23.4% and 12.7%, respectively. The amount of H₂O₂ in the leaf tissue of sorghum plant treated with 10 mM H₂O₂ was 0.7% of the applied amount after 1 hour. The level increased to approximately 1.0% after 6 hours. The highest antioxidant activity measured by the Oxygen Radical Absorbance Capacity assay was 847.3 µmol·g^-1 at 6 hour after treatment. However, in the well-watered condition, the concentration of H₂O₂ in the plant treated by the foliar application of H₂O₂ was 227.8 µmol·g^-1 higher than that of the untreated control. H₂O₂ treatment improved all the yield components and yield-related factors. Panicle length, plant dry weight, panicle weight, seed weight per plant, seed weight per unit area, and thousand seed weight were increased by 8.8%, 18.0%, 24.4%, 24.7%, 29.9% and 7.1%, respectively. Proteomic analysis showed that H₂O₂ treatment in sorghum increased the tolerance to drought stress and maintained growth and yield by ameliorating oxidative stress.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.232-241
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• 1997

The psychological problems following the experiences of school-violence could be more important than the physical problems. Victims could suffer from fear, depression, anger, lowered self-esteem, suicidal thought, and personality changes. To study the risk factors for school violence and the psychiatric problems after the experiences to school-violence provide us important informations to prevent and solve the problems of school violence. We examined clinical characteristics and psychosocial backgrounds of 13 adolescents who visited the psychiatric clinic after exposures to school violence from September, 1996 to May, 1997. The clinical data included intensity, motivations, durations, and methods of violence, psychiatric symptoms following exposure, findings of psychological test, and treatment course. The socioeconomic data included developmental characteristics of subjects, family characteristics, school life, and peer relationships. Of the 13 adolescents who experienced exposure to violence, 8 have experienced chronic psychiatric disturbances, 5 experienced transient psychiatric symptoms such as anxiety, depression, suicidal attempt who eventually returned to home and school life. Of the 8 adolescents who experienced chronic psychiatric disturbances, 4 experienced PTSD and depression lasting 3-6 months more, otherwise 4 showed converted features, such as aggressive behavioral disorder or perpetrator by strong compensatory effects after psychological shock. The subjects who have experienced chronic psychiatric disturbance have clinical characteristics such as physical or emotional abuse, physical illness or handicap, defects of ego functionings, and lack of family support. In summary, victims by school-violence manifested serious psychiatric disturbances, and they had clinically significant risk factors and some of them became perpetrators of school-violence.

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.1-9
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• 2011

Differentially Expressed Gene (DEG) was obtained from Differential Display Reverse Transcription (DDRT)-PCR using Annealing Control Primer (ACP) to search and clone genes related to developmental stages of Sebastes inermis. By using 120 ACPs, the nucleotide sequences obtained from 16 DEGs showing higher expression in 6-month-old skeletal muscle than 18-month-old ones and from 22 DEGs displaying stronger expression in 18-month-old than 6-month-old were analyzed and BLAST was conducted. The results identified that DEGs shared 69~95% homology with genes of parvalbumin (PVALB), nucleoside diphosphate kinase (NDK) B, tropomyosin (TPM), troponin I (TnI), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), muscle-type creatine kinase (CKM2), small EDRK-rich factor 2 (SERF2), adenosine monophosphate deaminase (AMPD), Trimeric intracellular cation channel type A (TRICA), Rho GTPase-activating protein 15 (ARHGAP15), S-formylglutathione hydrolase (Esterase D; ESD), heat shock protein 70 (hsp70), type 1 collagen alpha 2 (COL1A2), glutathione S-transferase, Mid1-interacting protein 1 (Mid1lip1), myosin light chain 1 (MYL1), sarcoplasmic/endoplasmic reticulum calcium ATPase 1B (SERCA1B), and ferritin heavy subunit (FTH1). Expression pattern by developmental stage of DEG14 and PVALB exhibiting strong expression in 6-month-old skeletal muscle was investigated using real time PCR. Expression was reduced as Sebastes inermis grew. Expression of PVALB gene was extremely low after 6 months of age. Expression of CKM2 showed higher expression in 18-month-old skeletal muscle than in 6-month-old muscles, and increased continuously until 4 years old, after which CKM2 expression became gradually reduced. By analysis of tissue-specific expression patterns of DEG, DEG14 was expressed mainly in skeletal muscle, liver, kidney and spleen tissues, whereas PVALB expression was expressed in skeletal muscle and kidney, but not in liver and spleen tissues. CKM2 was expressed in skeletal muscle, kidney, and spleen tissues, but not in liver tissues. PVALB gene was composed of 110 amino acids, which constituted 659 bp nucleotides. The results reported here demonstrate that the expression patterns of parvalbumin and CKM2 could be used as molecular markers for selecting fishes exhibiting fast growth.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.110-115
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• 2008

Purpose: Intussusceptions are one of the most common causes of intestinal obstruction in infants and young children. Although it is easily treated by non-operative reduction using barium, water or air, this treatment is very stressful for young patients and may cause bowel perforation, peritonitis and shock. In this study, we identified the risk factors associated with the failure of non-operative reduction, to identify a group of children that would benefit from the procedure and those who would not. Methods: We reviewed the medical records of patients with intussusception who were treated at the Korea University Medical Center Ansan hospital from March 1998 to July 2006. Three hundred fourteen children with intussusception were identified. Among them, non-operative reductions were performed in three hundred. Clinical and radiological variables were compared according to the failure or success of the non-operative reduction. Results: Non-operative reductions were successful in 243 (81%) and failed in 57 (19%). The group that had failed procedures had a younger age (12.3${\pm}$17.2 months vs. 18.0${\pm}$15.8 months, p=0.03), longer symptom duration before reduction (33.6${\pm}$29.0 hr vs. 21.5${\pm}$20.3 hr, p<0.01), more vomiting and lethargy (p<0.01), but less abdominal pain and irritability (p<0.01), compared with the group that had a successful procedure. Logistic regression analysis showed that the factors associated with the failure of non-operative reductions were a younger age, less than 6 months of age (odds ratio: 2.5, 95% confidence interval: 1.2~5.2, p=0.01), duration of symptoms, longer than 24 hrs before reduction (odds ratio: 2.1, 95% confidence interval: 1.2~4.2, p=0.03), bloody stool (odds ratio: 4.8, 95% confidence interval: 1.9~12.2, p<0.01), lethargy (odds ratio: 3.4, 95% confidence interval: 1.1~10.4, p=0.04), and abdominal pain or irritability (odds ratio: 0.2, 95% confidence interval: 0.1~0.4, p<0.01). Conclusion: For children with intussusception, an age younger than 6 months, and duration of symptoms more than 24 hrs before reduction, as well as the presence of bloody stools, lethargy and abdominal pain or irritability were variables associated with failure of a non-operative reduction. Knowledge of these variables should be considered in making clinical decisions for therapeutic interventions.

• Pediatric Infection and Vaccine
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• v.10 no.2
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• pp.186-192
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• 2003

Purposes : Recently, acute gastroenteritis broke out among the neonates transferred from postpartum care centers located in Seoul, and Gyeounggi area. Thus, we researched the cause, progress and characters of the disease by analyzing the cases from 9 hospitals in Seoul and Gyeounggi area. Methods : We conducted retrospective study of 33 neonates transferred from postpartum care centers from October 2001 to July 2002 : we divided the neonates into 2 groups. The severe group had any of following 5 conditions : blood pH <7.20, respiratory difficulty, mechanical ventilation, shock, and disseminated intravascular coagulation. And the rest were classified into the moderate group. Results : The severe group was significantly more aged than the moderate group(P= 0.005). Weight loss was significantly severe in the severe group(P=0.0512). In blood gas analysis, bicarbonate was less in the severe group than the moderate group(P=0.032). In the virus examination, rotavirus was detected in 7 cases, and astrovirus was detected in 1 case. In the severe group, 4 neonates were dead. Conclusion : In acute gastroenteritis of neonates, early diagnosis and treatment are important. Thus, the legislation of postpartum care center is needed, and the medical specialists should be stationed in postpartum care center. We assume that the severe group had severe conditions because they were treated comparatively late. However, to find out the cause of the disease and to cope with it, the nationwide epidemiologic study on acute gastrenteritis of neonates is needed.