• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.493-501
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• 2007

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP-complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et at suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. In the online scheduling, the NORA algorithm can find a schedule with the minimum total error for the imprecise online task system. In NORA algorithm, EDF strategy is adopted in the optional scheduling. On the other hand, for the task system with 0/1 constraint, EDF_Scheduling may not be optimal in the sense that the total error is minimized. Furthermore, when the optional tasks are scheduled in the ascending order of their required processing times, NORA algorithm which EDF strategy is adopted may not produce minimum total error. Therefore, in this paper, an online algorithm is proposed to minimize total error for the imprecise task system with 0/1 constraint. Then, to compare the performance between the proposed algorithm and NORA algorithm, a series of experiments are performed. As a conseqence of the performance comparison between two algorithms, it has been concluded that the proposed algorithm can produce similar total error to NORA algorithm when the optional tasks are scheduled in the random order of their required processing times but, the proposed algorithm can produce less total error than NORA algorithm especially when the optional tasks are scheduled in the ascending order of their required processing times.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.851-856
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• 2006

Purpose : The purpose of this study is to find out the diagnostic significance of serum bile acid on total parenteral nutrition induced cholestasis in premature infants. Methods : Infants without cholestasis were classified into postnatal days and each change of serum bile acid was measured and analyzed. Also, the serum direct bilirubin, serum bile acid, ${\gamma}$-glutamic acid transferase, and alkaline phosphatase of premature infants with total parenteral nutrition induced cholestasis were measured for comparison and analysis of their correlation. Results : Changes of serum bile acid analysis after birth showed no significant difference between boys and girls, between premature infants and term infants without cholestasis. Serum bile acid levels are constant after two weeks after birth in neonates without cholestasis. In premature infants with total parenteral nutrition induced cholestasis, the increase of serum direct bilirubin over 2 mg/dL was $34.9{\pm}18.3$ days after birth, and the increase of serum bile acid was $28.1{\pm}18.3$ days. Its increase was about 1 week faster than serum direct bilirubin, however, there was no statistical significance(P=0.114). Comparing analysis of serum bile acid, ${\gamma}$-glutamic acid transferase, and alkaline phosphatase, serum bile acid showed the highest correlation to serum direct bilirubin(r=0.487, P=0.000). Conclusion : Serum bile acid is an important parameter of total parenteral nutrition induced cholestasis in premature infants and will be useful for early diagnosis and treatment.

• 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 Chest Surgery
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• v.37 no.9
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• pp.749-754
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• 2004

Off-pump coronary artery bypass grafting (Off-Pump CABG) has been proven to have less morbidity and to facilitate early recovery. High-risk surgical patients may have benefitted by avoiding the adverse effects of the cardiopulmonary bypass. We compared the effectiveness of Off-Pump CABG with that of coronary artery bypass using cardiopulmonary bypass (On-Pump CABG) in high-risk patients. Material and Method: 682 patients (424 Off-Pump CABG and 258 On-Pump CABG) underwent isolated coronary artery bypass grafting between January 2001 and June 2003. Patients who were considered high risk were selected High risk is defined as the presence of one or more of nine adverse prognostic factors. Data were collected from 492 patients in Off-Pump CABG and 100 in On-Pump CABG for risk factors, extent of coronary disease, and in-hospital outcomes. Result： Off-Pump CABG group and On-Pump CABG group did not show differences in their preoperative risk factors. We used more arterial grafts in Off-Pump CABG group (p < 0.05). Postoperative results showed that operative mortality (0.5% in Off-Pump CABG versus 2.0% in On-Pump CABG), renal failure (2.6% in Off-Pump CABG versus 7.0% in On-Pump CABG), and perioperative myocardial infarction (1.5% in Off-Pump CABG versus 1.0% in On-Pump CABG) did not differ significantly. However, Off-Pump CABG had shorter mean operation time (p<0.05), lower mean CK-MB level (p <0.05), lower rate of usage of inotropics (p < 0.05), shorter mean ventilation time (p <0.05), lower perioperative stroke (0% versus 2.0%), and shorter length of stay (p < 0.05) than On-Pump CABG. On-Pump CABG had more distal grafts (p<0.05) than Off-Pump CABG. Although Off-Pump CABG and On-Pump CABG did not show statistical differences in mortality and morbidity was more frequent in CABG. Conclusion: Off-Pump CABG reduces morbidity and favors hospital outcomes. Therefore, Off-Pump CABG is safe, reasonable and may be a preferable operative strategy for high-risk patients.

• Journal of Chest Surgery
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• v.31 no.11
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• pp.1049-1055
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• 1998

Background: Coronary artery bypass surgery is an important treatment for ischemic heart disease. Recently operative mortality and morbidity has decreased, however further improvement is necessary. Materials and methods: This study was designed to evaluate the risk of operative mortality and morbidity by retrospective method. From 1992 to 1997, eighty six patients underwent coronary artery bypass surgery. There were 61 males and 25 females aged 36~74 years(mean, 58.6). Fourteen patients(16%) had previous PTCA or stent insertion, 41 patients(48%) had unstable angina, and 45 patients(52%) had three vessel disease. Patients with low LV ejection fraction(<35%) were 7 cases and urgent or emergent operation were 10 cases. There were 6 cases of combined surgery which were mitral valve replacement(2 cases), aortic valve replacement(2 cases), ASD repair(1 case), and VSD repair(1 case). Average number of distal anastomosis was 3.5 per patient and average aortic cross clamp time was 115±38.3min. Preoperative risk factors were defined as follows: female, old age(>70 years), low body surface area(<1.5M2), PTCA or stent insertion history, hypercholesterolemia, smoking, hypertension, DM, COPD, urgent or emergent operation, left main disease, low LV ejection fraction(<35%), and combined surgery. Results: Operative mortality was 7cases(8%). As a postoperative morbidity, perioperative myocardial infarction was 6 cases, cerebrovascular accident 6 cases, reoperation for bleeding 5 cases, acute renal failure 4 cases, gastrointestinal complication 3 cases, and mediastinitis 3 cases. In the evaluation of operative risk factors, low body surface area, DM and low LV ejection fraction were found to be predictive risk factors of postoperative morbidity(p<0.05), and low ejection fraction was especially a risk factor of hospital mortality(p<0.05). Conclusions: In this study, low body surface area, DM and low LV ejection fraction were risk factors of postoperative morbidity and low ejection fraction was a risk factor of hospital mortality.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.75-82
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• 2020

The purpose of this study was to establish optimized extraction conditions for Lilium bulb and Lespedeza cuneata G. Don and to investigate the storage stability of beverages containing extracts. The hot-water extract and the 60% ethanol extract had the highest DPPH radical scavenging activities as well as the highest total polyphenol content. The total polyphenol content, total flavonoid content and DPPH radical scavenging activity were the highest when the Lilium bulb extract was mixed with the Lespedeza cuneata G. Don extract at the ratio of 1:4. Storage stability of beverages was determined during storage at 10, 25, and 35℃ for 6 months. The pH was decreased from 4.15 to 4.01-4.05, while the acidity was increased from 0.60% to 0.70-0.75% after storage for 6 months. The soluble solid contents were not changed during storage of 6 months. The DPPH radical scavenging activity was decreased after 4-6 months. The Hunter b (yellowness) values decreased at 35℃ after storage for 6 months while the lightness (L) and redness (a) were not changed during storage for 6 months. The total saponin content was not remarkably changed during 2 months of storage, while it decreased after 4-6 months of storage. The flavonoid content was decreased 47% and 55% from an intial 21.7 mg/100 mL to 10.3 mg/100 mL and 12.0 mg/100 mL after 1 month of storage and then remained stable until 6 months. General bacteria and coliform group were not detected during storage for 6 months.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.42-51
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• 2001

Background : Recently, cardiopulmonary exercise testing (CPX) has become a popular diagnostic method for differentiating the main cause of exertional dyspnea or exercise limitation. We evaluated the difference in the CPX results according to interpretative algorithms and the methals of exercise in Korea. Method : Sixty-six patients with chronic lung disease and 48 adults with dyspneic symptoms, but with no abnormalities in a spirometry performed symptom limited CPX, were included in this study. The results were interpreted using both Wasserman's(WA) and Eschenbacher's algorithm (EA), and a comparison between both algorithms was made. Thirty-three healthy medical students performed the CPX with a cycle ergometer and treadmill. The results were interpreted with EA and the concurrence in interpretations was evaluated accord ing to the methods of exercise. Results : 1. In patients with chronic lung disease, the overall concordance rate between the two algorithms was 63.6%. The concordance rates waw 69.8% in patients with obstructive, 25.0% in those with restrictive, and 66.7% in those with mixed pulmonary insufficiency. In patients with dyspneic symptoms but normal findings in resting spirometry, the concordance rate was 60.4%. 2. In healthy medical students, in results inter preted with EA, the concordance rate between the cycle ergometer and treadmill exercise was 25.0%. Conclusion : Both interpretative algorithms and methods of exercise may affect the CPX results. In using CPX as a diagnostic test for the causes of dyspnea in the Korean population. the interpretative algorithms and method of exercise need to be standardized, and a predictive $VO_2$max equation needs to be established.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.763-769
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• 2009

Background: In the majority of cases, sternal instability and wound infection concomitantly present after a cardiac operation following conventional median sternotomy, and these complications have a major influence on the postoperative course. The aim of this study is to compare the results of the different sternal wiring techniques of sternal infection. Material and Method: Between April 2004 and December 2008, 157 adult patients underwent cardiac in group A, whereas 71 patients who had undergone modified Robicsek sternal wiring were included in group B. The incidences of sternal wound complications in the two groups were assessed. Result: The mean age of the group B patients was older than that of the group A patients ($61{\pm}10$ years vs $57{\pm}13$ years). The incidence of preoperative left ventricular dysfunction (ejection fraction <30%), chronic obstructive pulmonary disease, renal failure requiring dialysis and diabetes mellitus were significantly higher in Group B, whereas the other perioperative risk factors for infection were not significantly different between the two groups. Two patients in group A experienced superficial wound infection, whereas 4 patients in group B displayed superficial wound infection, but the difference was not statistically significant (p=0.255). Yet poststernotomy deep sternal wound infection appeared in 6 patients of group A, whereas none of the patients in group B displayed this malady. Conclusion: The modified Robicsek sternal wiring technique showed greater sternal stability even for the patient with a high risk for infection, and the technique caused a lower incidence of deep sternal wound infection.

• Tuberculosis and Respiratory Diseases
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• v.58 no.2
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• pp.152-159
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• 2005

Background : Exacerbations of chronic obstructive pulmonary disease (COPD) are thought to be associated with increased airway inflammation, and the $NF-{\kappa}B$ is known to be an indicator of cellular activation and of inflammatory mediator production. This study was undertaken to investigate the change of cytokine characteristics and $NF-{\kappa}B$ activity in induced sputum of COPD patients during exacerbation and recovery of the disease. Methods : Sputum induction was performed in 37 patients with COPD during exacerbation and during recovery and in 15 healthy subjects. Cell counts, levels of IL-6, IL-8 and $TNF-{\alpha}$ in induced sputum and NF-kB activity in macrophage of induced sputum were measured. Results : Patients with COPD showed significantly increased levels of IL-6, IL-8 and $TNF-{\alpha}$(p<0.01) and increased $NF-{\kappa}B$ activity in induced sputum(p<0.05) as compared with control subjects. Level of IL-8 during exacerbation of COPD decreased significantly during recovery(p<0.05). $NF-{\kappa}B$ activity and levels of IL-6 and $TNF-{\alpha}$ tended to be decreased during recovery, but not siginificantly. Conclusion : Activation of $NF-{\kappa}B$ and increased levels of IL-6, IL-8 and $TNF-{\alpha}$ were thought to be associated with pathogenesis and exacerbations of COPD.

• Tuberculosis and Respiratory Diseases
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• v.65 no.1
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• pp.15-22
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• 2008

Background: Lung cancer is the leading cause of cancer death in South Korea since the year 2000 and it is more common in elderly patients, with a peak incidence at around 70~80 years of age. However, these elderly patients receive treatment less often than do the younger patients because of organ dysfunction related to their age and their comorbidities, and they show poor tolerance to chemotherapy. The aims of this study were to analyze the clinical characteristics and treatment-related survival of elderly patients with lung cancer. Methods: In this retrospective study, we analyzed the clinical data of 706 lung cancer patients who were diagnosed at hospitals in Daegu and Gyeongsangbukdo from January 2005 to December 2005. We compared the clinical characteristics and outcomes of the patients who were aged 70 years and older (elderly patients) with those clinical characteristics and outcomes of the younger individuals. Results: The median age of the patients was 68 years (from 29 to 93) and the elderly patients were 38.7% (n=273) of all the study's patients. Squamous cell carcinoma was the most common type of lung cancer in both the elderly and younger patient groups. Elderly patients had more symptoms of dyspnea and chronic obstructive pulmonary disease (COPD) than the younger patients (p<0.001 and p<0.001, respectively). A good performance status (ECOG 0-1) was less common for the elderly patients (p<0.001). The median survival of the non-small cell lung cancer (NSCLC) patients was significantly higher in the younger patient group than in the elderly patient group (962 days vs 298 days, respectively, p=0.001). However, the median survival of the NSCLC patients who received any treatment showed no significant difference between the younger patient group and the elderly patient group (1,109 days vs 708 days, respectively, p=0.14). Conclusion: Our data showed that appropriate treatment for selected elderly patients improved the survival of patients with NSCLC. Therefore, elderly NSCLC patients with a good performance status should be encouraged to receive appropriate treatment.