• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1001-1009
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• 2000

This study is to find the utilization of intermittent aeration system, around S-COD, T-COD, SS, timewise changes of treatment performance, sludge conversion yield, changes of temperature and pH, etc. In consequence of this study, factors of temperature correction showed 1.052 on continuous aeration, and 1.056 on intermittent aeration which is more sensitive to temperature through a minute degree. Meanwhile, sludge conversion yield on intermittent aeration showed lower and more economical than that on continuous aeration. In case of changing pH, treatment water of both reactors worsened slightly in acid but improved in alkali. In general. considering the quality of effluent water, variation pH of effluent water, etc. the case of intermittent aeration was more favorable than that of continuous aeration.

• Journal of Gastric Cancer
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• v.7 no.2
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• pp.74-81
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• 2007

Purpose: Routine pancreatico-splenectomy with total gastrectomy should no longer be considered as the standard surgical procedure for gastric cancer because of the lack of proven surgical benefit for survival. The aim of this study is to evaluate the clinicopathologic factors and the survival of patients with locally advanced gastric cancer and they had undergone combined pancreatico-splenectomy with a curative intent. Material and Methods: We retrospectively reviewed a total of 118 patients who had undergone total gastrectomy with distal pancreatico-splenectomy from 1990 to 2001. The patients were divided into 2 groups: 90 patients who were free from cancer invasion (group I), and 28 patients with histologically proven cancer invasion into the pancreas (group II). The various clinicopathologic factors that were presumed to influence survival and the survival rates were analyzed. Results: The rate of pathological pancreatic invasion was 23.7%. The tumor stage, depth of invasion, pancreas invasion, lymph node metastasis, lymph node ratio, curability and the hepatic and peritoneal metastasis were statistically significance on univariate analysis. Among these factors, the tumor stage, lymph node ratio and curability were found to be independent prognostic factor on multivariate analysis. The 5-years survival rates were 36.2% for group I and 13.9% for group II. The morbidity rate was 22.1%, and this included pancreatic fistula (5.1%), intra-abdominal abscess (4.2%) and bleeding (4.2%). The overall mortality rate was 0.8%. Conclusion: Combined distal pancreatico-splenectomy with total gastrectomy with a curative intent was selectively indicated for those patients with visible tumor invasion to the pancreas, a difficult complete lymph node dissection around the distal pancreas and spleen, and no evidence of liver metastasis or peritoneal dissemination.

• International Commerce and Information Review
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• v.16 no.5
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• pp.409-433
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• 2014

In this paper, I estimate long-run elasticities of US real GDP and real exchange rate between Korean Won and US Dollar on export of Korean goods to US and analyze changes in their trend by using VECM and rolling regression with a fixed window. For the purposes I use the year data from 1990 to 2013 which are selected from UNCTAD, Korea Trade Association(KTA), and Bank of Korea(BOK). The results are that the long-run elasticities of US real GDP vary from 2.849 to 2.938 for the period from 1990 to 2013 depending on the models in VECM and all of them are significant statistically. The elasticities of real exchange rate between Korean WON and US Dollar vary from 0.962 to 0.967 for the same period depending on the models in VECM and all of them are significant statistically. In case of the results through the OLS and the rolling regression, the long-run elasticities of US. real GDP are 3.015 for Basic Model, 2.949 for the modified Model 1, and 2.125 for the modified Model 2 for the period from 1990 to 2013 depending on the models and all of them are significant statistically. The average of long-run elasticities of real US GDP before the global financial crisis of 2008 is greater than that after the global financial crisis of 2008. On the other hand, the long-run elasticities of real exchange rate between Korean WON and US $ are 0.347 for Basic Model, 0.566 for the modified Model 1, and -0.217 for the modified Model 2 for the same period and all of them are significant statistically except for the modified Model 2. The average of long-run elasticities of real exchange rate before the global financial crisis of 2008 is greater than that after the global financial crisis of 2008.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.285-294
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• 2012

Under conditions of increasing environmental uncertainty, firms' risk management become important. This study examines the impact of foreign currency derivative usage on firm value using 3,004 Korean non-financial firms from 2002 to 2007. The results showed that there was no significant relationship between foreign currency derivative usage and firm value for the whole period and from 2002 to 2004 when exchange rate was relatively less volatile. But form 2005 to 2007 when exchange rate was volatile, foreign currency derivative usage gave significant negative impact on firm value, whereas when contract value was used, the relatinship was significantly positive. These results might be come from the characteristics of contract value and fair value of foreign currency derivatives. increased firm value when contract value was used as foreign currency derivative usage measure. But when fair value was used, there was no significance. For control variables, major shareholders ownership and foreign blockholders ownership was positively related with firm value.

• KDI Journal of Economic Policy
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• v.36 no.3
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• pp.1-23
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• 2014

This paper has studied the monetary policy in Korea with a time varying VAR model using four key macroeconomic variables. First, inclusion of the exchange rate was a crucial factor in evaluating Korean monetary policy since the monetary policy demonstrated sensitivity to exchange rate movements during the crisis periods of both the Asian financial crisis of 1997 and the global financial crisis of 2008. Second, a specification of the stochastic volatilities in TVP-VAR model is important in explaining excessive movements of all variables in the sample. The overall moderation of variables in 2000s was more or less due to a reduction of the stochastic volatilities but also somewhat due to the macroeconomic fundamental structures captured by impulse response functons. Third, the degree of the monetary policy effectiveness of inflation was mitigated in recent periods but with increased persistence. Lastly, the monetary policy stance towards inflation stabilization has advanced ever since the inflation targeting scheme was adopted. However, there still seems to be a room for improvement in this aspect since the degree of the monetary policy stance towards inflation stabilization was relatively weaker than to output stabilization.

• Childhood Kidney Diseases
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• v.15 no.1
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• pp.14-21
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• 2011

Although left Left ventricular hypertrophy (LVH) is not only an adaptive response of the heart to increased cardiac workload in hypertension, it surelybut also is the most potent risk factor of overt cardiovascular complications such as coronary heart disease, heart failure, arrhythmia and stroke in the hypertensive population. Also it has become generally accepted that subclinical cardiovascular disease begins in childhood and LVH is the most readily assessed marker for that. As LVH can be seen in children and adolescents with even mild blood pressure elevation with the reported prevalence of 10 to 47%, aggressive antihypertensive treatment is critical in preventing the development of hypertensive heart disease in that those cases.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1159-1164
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• 1998

Background: Although operative outcome is progressing due to the development of operative techniques and myocardial protection, some patients face an increased morbidity and mortality. Therefore, it has become increasingly important to predict the operative morbidity and mortality. Material and Method: This retrospective study reports the results of risk factor analysis of morbidity and mortality of 137 consecutive patients who were underwent coronary artery bypass graft surgery(CABG). Preoperative variables were age, sex, preoperative myocardial infarction, operative priority, left ventricular ejection fraction, obesity and triple vessel disease. Postoperative morbidities were arrhythmia, wound infection, cerebral infarction, prolonged postoperative hospitalization, pneumonia, acute renal failure, prolonged use of ventilator and operative death. Result: The mean age of total patients was 56.7 years, from 27 to 74. The overall mortality was 6.6%(9 of 137) with the mortality of 3.9%(5 of 128) for elective operation, and 44.4%(4 of 9) for emergent or urgent cases. The morbidity of patients over 65 years was stastistically higher than that of under 65 years. Sex distribution showed no difference in morbidity, however operative mortality rate was slightly higher in women (5/41, 12.19%) than in men(4/96, 4.17%). Morbidity of emergent or urgent operation was 100%, much higher than that of the elective operation. Mortality of the patients whose left ventricular ejection fraction was under 50% was higher than that of those over 50%. Conclusion: We concluded that the risk factors of morbidity after CABG were old age above 65 years and emergent or urgent operation, and that risk factors of mortality were low left venticular ejection fraction under 50% and emergent or urgent operation.

• The Korean Journal of Medicine
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• v.93 no.6
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• pp.548-555
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• 2018

Background/Aims: Assessment of fluid status in hemodialysis patents is very important. Overhydration in hemodialysis is associated with generalized edema, cardiovascular complications, and hypertension. The aim of this study was to determine the factors correlated with mortality of hemodialysis patients, assessing body muscle mass and fluid status using bioelectrical impedance analysis (BIA). Methods: This study enrolled 93 patients who underwent hemodialysis between January 2010 and May 2015 at CHA Bundang Medical Center. Medical records of enrollees up to June 2017 were reviewed retrospectively. These included laboratory results (serum albumin, C-reactive protein [CRP], lipid profile, etc.) and BIA data (extracellular water, intracellular water, total body water, soft lean mass, fat free mass, skeletal muscle mass, etc.). Results: Eleven of 93 patients had expired by May 2017. Among the surviving subjects, mean age was younger, CRP levels were lower, albumin levels were higher, and extracellular water/total body water (ECW/TBW) ratios were lower than in the expired patient group. Kaplan-Meier survival analysis revealed that overhydration (ECW/TBW > 0.4) was associated with higher mortality. Conclusions: In hemodialysis patients, overhydration is an important factor in mortality, and BIA could be a reliable modality in its assessment. We suggest that, for hemodialysis patients, overhydration is more of a risk factor for mortality than is muscle wasting.

• KOREAN POULTRY JOURNAL
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• v.40 no.12
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• pp.98-100
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• 2008

2008년 새해를 맞이하면서 좀 더 나은 삶을 간절히 기도했다. 오직 나뿐만 아니었을 것이다. 그러나 간절한 기도는 고통으로 물든 은행나무 잎처럼 우리들 가슴을 새까맣게 물들이고 말았다. 우리 육계인은 품질 좋은 병아리와 사료를 공급 받아 좋은 닭고기를 생산하기 위해 지극 정성으로 키우고 있다. 그런데 올봄에는 느닷없이 조류인플루엔자 발생으로 전국을 떠들썩하게 했다. 국민에게 위압감을 주는 과잉보도로 소비는 바닥으로 떨어지고 말았다. 육계인들은 말로 표현할 수 없는 엄청난 고통을 당했다. 그 고통이 사라지기도 전에 곡물 파동까지 이어져 사료공급이 중단될 위기까지 겪고 있을 때 원유 폭등과 환율 폭등으로 우리 육계인들의 마음은 한시도 편한 날이 없는 한 해였다. 폭풍우 같은 한해가 지나가자 한미 FTA도 우리 육계 산업에 크나큰 걸림돌이 아닐 수 없다. 다행히도 정부와 여, 야 모두 관심을 가지고 있다. 그 관심에 희망과 용기를 가져본다.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.29-43
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• 1997

An integrated optimal control modelhas been formulated to address dynamic freeway diversion control process. The purpose of this paper is to develop an effective and efficient approach for simultaneous]v solving optimal control measures, including on-ramp metering rates, off-ramp diversion rates, and g/C ratios for traffic signals, on a real-time basis. By approximating the flow-density relation with a two-segment linear function, the non-linear optimal control problem can be simplified into a set of piece-wised linear programming models and solved with the proposed SLP algorithm. consequently, an effective on-line feedback method has been developed for integrated freeway corridor control in the framework of the ITS