• The Korean Journal of Applied Statistics
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• v.15 no.1
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• pp.57-71
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• 2002

We introduce three types of exponential survival models, such as simple model, change-point model and finite mixture model in this paper. Among these models, in order to choose the best model, the model choice method is proposed using Gelfand and Ghosh(1998)'s idea. Then to avoid the computational difficulties, data augmentation method (Tanner and Wong, 1987) and Gibbs sampler (Gelfand and Smith, 1990) are employed. Our methodology is applied to both simulated data and Stangl (1991)'s On-impramint Hydrochloride data.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1225-1238
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• 2015

In this research, we fit various survival models and conduct tests and estimation for the hazard change-point with the rectal cancer data. By the log-rank tests, at significance level ${\alpha}=0.10$, survival functions are significantly different according to the uniporter of glucose (GLUT1), clinical stage (cstage) and pathologic stage (ypstage). From the Cox proportional hazard model, the most significant covariates are GLUT1 and ypstage. Assuming that the rectal cancer data follows the exponential distribution, we estimate one hazard change-point using Matthews and Farewell (1982), Henderson (1990) and Loader (1991) methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.255-261
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• 2013

In this paper, we developed and tested a program for prediction flash fire in a combat system. Purposes of the program are flash fire prediction of combat system for analysis vulnerability and survivability, and visualization for fire-related information. To do this, we defined critical components of the combat system which has probabilities of flash fire occurrence, and proposed Flash Fire Probability Tree which is based on Fault Tree Analysis(FTA). The program visualizes positions of critical components in combat system, positions of penetrated components, selected Flash Fire Probability Tree, temperature profile, and tables for properties of matters.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.550-553
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• 2018

The lifespan of bats is longer compared to that of other similarly sized mammals, and it is recorded that some bats' lifespan is more than 30 years. However, it is known that the lifespan of Pipistrellus abramus using human residential areas as their habitats is less than five years. We have put aluminum rings on the forearms of 284 P. abramus starting from 2008. Interestingly, in June 2018, a female adult bat was recaptured ten years after the aluminum ring was attached. The results of this study on the lifespan of P. abramus is new and it's likely to form the baseline for lifespan studies and habitat management of P. abramus in the future.

• Journal of Aquaculture
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• v.18 no.3
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• pp.154-159
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• 2005

This study was conducted to evaluate the effects of size grading on growth, feed efficiency and survival of juvenile olive flounder. Juvenile flounder were divided into four groups by initial average size; Small group $(1.3{\pm}0.23g)$, medium group $(3.1{\pm}0.45g)$, large group $(4.9{\pm}0.57g)$ and ungraded group $(3.3{\pm}1.66g)$. Triplicate groups of 100 fish were reared over 8 weeks. In final body weight distribution, frequency of the small size flounder (10 g) was markedly higher in the ungraded group than in the small group. Specific growth rate, feed efficiency and survival in the ungraded group were significantly lower (P<0.05) than those in the pooled data of the othor three graded groups, although feed intake in the ungraded group was significantly higher (P<0.05) than that of the pooled data of the other three graded groups. These results show that the small flounder gained significantly faster growth and higher survival in the absence of the large flounder. Therefore, size grading seems to be an important and necessary operation to improve the growth and survival of juvenile olive flounder (1-5 g).

• Journal of Chest Surgery
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• v.31 no.2
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• pp.149-154
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• 1998

We retrospectively analyzed 54 patients with esophageal cancer treated surgically between 1992 and 1996. They composed of 51(94.4%)men, 3(5.6%)women, and the age ranged from 42 to 78, the mean was 58.7$\pm$8.37. Symptoms were varied with dysphagia(72.2%), epigastric discomfort(16.6%), chest pain (5.6%), and so on(5.6%). Transthoracic esophagectomy(TTE) with esophagogastrostomy was done in 36 case, TTE with esophagocologastrostomy in 4 case, and transhiatal esophagectomy(THE) with esophagogastrostomy in 14 case. The operative mortality was 12.9%(7/54); 6 underwent TTE with esophagogastrostomy, and 1 underwent TTE with esophagocologastrostomy. Postoperative complications were of anastomotic leakage in 7 case, wound infection in 10 case, anastomotic stricture in 9 case, vocal cord paralysis in 2 case, bronchial tearing in 1 case, and pneumothorax in 3 case. Locations of esophageal cancer were upper thoracic esophagus in 4 case, middle thoracic esophagus in 34 case and lower thoracic esophagus in 16 case. Histological types were adenocarcinoma in 1 case and squamous cell carcinoma in 53 case. During the follow-up period, 25 cases died. Cumulative survival rate was 52.7% in 1 year, 45.5% in 2 year, 45.5% in 3 year, 45.5% in 4 year, 45.5% in 5 year.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.208-214
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• 2003

Four species of water fleas (Daphnia magna, Daphnia pulex, Daphnia galeata, and Moina macrocopa) were examined for the clarification of their reproduction with culture conditions. The reproduction tests of water flea by the culture conditions were carried out. For the comparison of the reproduction rate, five media (manure-soil medium, DIN medium, M4 medium, EPA medium, fertilizer medium) were applied to determine the best medium. Daphnia magna, Daphnia pulex, and Moina macrocopa were appeared the best reproduction in the manure-soil medium at $20^{\circ}C.$ The lifespan and young reproduction were better in manure-soil medium than the others. But Daphnia galeata was lived for 34 days in the fertilizer medium at $20^{\circ}C.$ The culture of Daphnia galeata was difficult to rear than the other species. In the current study, the microcystin of Microcystis sp. did not particularly affect on the survival of water fleas. But the lifespan was short and the reproduction rate was low. Therefore water flea have a preference for Scenedesmus sp. than Microcystis sp. On the condition of the feeding Scenedesmus sp., all examined water fleas appeared to have the longest lifespan and the most young water fleas produced at any medium and temperature as compared with the feeding the Microcystis sp. For the culture temperature, the lifespan was longer on $20^{\circ}C$ than $15^{\circ}C$.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.2
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• pp.88-94
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• 2021

Purpose: The purpose of this study was to evaluate the anti-inflammatory effects of non-thermal atmospheric pressure plasma (NTP) on human gingival fibroblasts (HGFs) for clinical application of periodontal treatment. Materials and Methods: HGFs were treated with Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS). Customized NTP device was developed for periodontal in vitro study. Cell viability was evaluated with cell counting kit-8. The levels of inflammatory cytokines, including interleukin (IL)-8 and 6, were determined by enzyme-linked immunosorbent assay. Results: When NTP was applied, the cell viability did not change significantly, and there was no difference for 6 h and 24h. When Pg LPS was treated to HGFs, the secretion of IL-8 and IL-6 was increased compared to the control group. But when the NTP was applied, the secretion of them was significantly decreased. Conclusion: NTP did not affect cell viability of HGFs. And it inhibited the LPS-induced production of IL-8 and IL-6.

• Journal of Gastric Cancer
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• v.5 no.1
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• pp.29-33
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• 2005

Purpose: To determine the prognostic values of the hematologic parameters checked preoperatively in gastric cancer patients, we evaluated and compared the relationship between hematologic parameters and clinicopathologic factors of gastric cancer patient. Materials and Methods: The medical records of 357 consecutive patients who had undergone surgery for gastric cancer at the Department of Surgery, Hanyang University Hospital, between Dec. 2,000 and Dec. 2003 were reviewed. To exclude any adverse effect of invasive procedures to hematologic parameters, the samples taken immediately at outpatient department was used. The normal range of serum albumin was defined above 3.5 g/dl, serum hemoglobin above 12 g/dl, and serum platelet count under $400\times10^{3}{\mu}l$. Patients were defined as group 1 when any of these parameters was abnormal, and defined as group 2 when all parameters were normal. The relationships between hematologic parameters and survival rate were investigated. Results: The mean values of platelet count increased, but level of serum albumin and serum hemoglobin decreased significantly according to the advancement of the disease stage (P=0.000). The differences of depth of tumor invasion and lymph node metastasis between the group 1 and the group2 was statistically significant (P=0.001). Three-year survival difference between group 1 and group 2 was significant (P=0.037). Conclusion: The hematologic parameters checked preoperatively in patients of gastric cancer are simple and cheap, meanwhile reflect the general condition of the patients. Any presence of anemia, hypoalbuminemia, or thrombocytosis can predict the progression of the disease and poor survival rates.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.221-227
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• 2002

Purpose : To evaluate the role of postoperative chemoradiotherapy in locally advanced rectal cancer, we retrospectively analyzed the treatment results of patients treated by curative surgical resection and postoperative chemoradiotherapy. Materials and Methods : From April 1989 through December 1998, 119 patients were treated with curative surgery and postoperative chemoradiotherapy for rectal carcinoma in Gyeongsang National University Hospital. Patient age ranged from 32 to 73 years, with a median age of 56 years. Low anterior resection was peformed in 59 patients, and abdominoperineal resection in 60. Forty-three patients were AJCC stage II and 76 were stage III. Radiation was delivered with 6 MV X rays using either AP-PA two fields, AP-PA both lateral four fields, or PA both lateral three fields. Total radiation dose ranged from 40 Gy to 56 Gy. In 73 patients, bolus infusions of 5-FU $(400\;mg/m^2)$ were given during the first and fourth weeks of radiotherapy. After completion of radiotherapy, an additional four to six cycles of 5-FU were given. Oral 5-FU (Furtulone) was given for nine months in 46 patients. Results : Forty $(33.7\%)$ of the 119 patients showed treatment failure. Local failure occurred in 16 $(13.5\%)$ patients, 1 $(2.3\%)$ of 43 stage II patients and 15 $(19.7\%)$ of 76 stage III patients. Distant failure occurred in 31 $(26.1\%)$ patients, among whom 5 $(11.6\%)$ were stage II and 26 $(34.2\%)$ were stage III. Five-year actuarial survival was $56.2\%$ overall, $71.1\%$ in stage II patients and $49.1\%$ in stage III patients (p=0.0008). Five-year disease free survival was $53.3\%$ overall, $68.1\%$ in stage II and $45.8\%$ in stage III (p=0.0006). Multivariate analysis showed that T stage and N stage were significant prognostic factors for five year survival, and that T stage, N stage, and preoperative CEA value were significant prognostic factors for five year disease free survival. Bowel complication occurred in 22 patients, and was treated surgically in 15 $(12.6\%)$, and conservatively in 7 $(5.9\%)$. Conclusion : Postoperative chemoradiotherapy was confirmed to be an effective modality for local control of rectal cancer, but the distant failure rate remained high. More effective modalities should be investigated to lower the distant failure rate.