• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.467-474
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• 2014

Preliminary design in chemical process furnishes economic feasibility through calculation of both mass balance and energy balance and makes it possible to produce a desired product under the given conditions. Through this design stage, the process possesses unchangeable characteristics, since the materials, reactions, unit configuration, and operating conditions were determined. Unique characteristics could be very economic, but it also implies various potential risk factors as well. Therefore, it becomes extremely important to design process considering both economics and safety by integrating process simulation and quantitative risk analysis during preliminary design stage. The target of this study is LNG liquefaction process. By the simulation using Aspen HYSYS and quantitative risk analysis, the design variables of the process were determined in the way to minimize the inherent explosion risks and operating cost. Instead of the optimization tool of Aspen HYSYS, the optimization was performed by using stochastic optimization algorithm (Covariance Matrix Adaptation-Evolution Strategy, CMA-ES) which was implemented through automation between Aspen HYSYS and Matlab. The research obtained that the important variable to enhance inherent safety was the operation pressure of mixed refrigerant. The inherent risk was able to be reduced about 4~18% by increasing the operating cost about 0.5~10%. As the operating cost increases, the absolute value of risk was decreased as expected, but cost-effectiveness of risk reduction had decreased. Integration of process simulation and quantitative risk analysis made it possible to design inherently safe process, and it is expected to be useful in designing the less risky process since risk factors in the process can be numerically monitored during preliminary process design stage.

• Journal of Korean Academy of Nursing
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• v.19 no.1
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• pp.40-62
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• 1989

This study was conducted to measure the effects of clinical application of a Nursing Diagnosis Protocol. The dependent variables were the degree of patient's satisfaction and the degree of nurse's satisfaction with the nursing activity. Analysis of the effect of the use of the nursing diagnosis protocol was based on the nursing record. The subjects for this study were 61 nurses(experimental group 31, control group 30) and 155 patients (experimental group 55, control group 100) on four internal medicine wards in K University Hospital in Seoul. Data collection was done from August to October 12,1988. The results obtained in this study can be summarized as follows, 1, Effect of the clinical application of the nursing diagnosis protocol. 1) The first hypothesis ; “nurses who use the nursing diagnosis protocol will have higher degrees of satisfaction than those who use traditional methods” was rejected (t＝.54, df＝58, p＝.59). 2) The second hypothesis ; “patients nursed by nurses using the nursing diagnosis protocol will have higher degrees of satisfaction than those nursed with traditional methods” was supported(t＝1.93, df＝154, p＝.05). 3) The third hypothisis : Major hypothesis ; “the nursing records of the experimental group, who used the nursing diagnosis protocol, will be more detailed than those of the control group” was supported (t＝6.40, df＝79.90, p＝.000). (1) The first subhypothesis ; “The recorded data collection of the experimental group will be more detailed than that of the control group” was rejected (t＝1.79, df＝118, p＝.07). (2) The second subhypothesis ; “The recorded patient's problem statement of the experimental group will be more detailed than that of the control group”, was supported. (3) The third subhypothesis ; “The nursing record of the experimental group will be more convenient for implementation than that of the control group” was supported. 2. Factors related to the nurse's degree of satisfaction with protocol. 1) No general characteristics(age, religion, education level, duty career, present duty career) were related to the nurse's degree of satisfaction. 2) Variables related to the nurse's degree of satisfaction were “satisfaction as a nurse” and “consider nursing as lifelong job” (t＝-2.6, df＝13.22, p＝.02, t＝2.41, df＝23.85, p＝.02). 3. Factors related to the patient's degree of satisfaction. 1) General characteristics related to the patient's degree of satisfaction with nurses using the protocol were age, educational level, and being married.(F＝5.17, df＝3/153, p＝.00, t＝ -2.39, df＝154, p＝,01, f＝5.91, df＝2/153, p＝.00) 2) The variables previous hospitalization, duration of hospitalization, the hospital unit presence of a relative, medical insurance, or medical diagnosis were not related to the patient's degree of satisfaction. 1. The experimental group's nursing record was more detailed than the control group's record with regard to the physical and psychological state of the patients. As noted above, the experimental group nurses, who use a nursing diagnosis had protocol were less satisfied than the control group who used traditional methods of the recording, but experimental group patients had a higher degree of satisfaction than the control group patients. The nursing records of experimental group, using the nursing, diagnosis protocol was more detailed than that of the control group. If the nursing diagnosis protocol is used in clinical nursing practice, the quality of nursing care may be improved.

• Journal of Korean Academy of Nursing
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• v.8 no.2
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• pp.63-77
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• 1978

Studies pertaining to influential factors on adoption and practice of family planning are very much needed to lower fertility, for family planning has regarded as only one social acceptable means to curb the accelerated population growth. One of the influential factors is known as rumors on family planning methods that hinder the actual practice of family planning. This study generally aimed at disclosing rumors on family planning methods prevalent in rural communities so that one could gain some in sights to cope with the ill effects of rumors to promote family planning Practice in rural communities in Korea. In order to accomplish the general aims this study formulated following four specific objectives; 1. Find out types and frequencies of rumors exposed of contraceptive methods. 2. Find out the relationship between the rumors exposed and socio-economic and demographic characteristics of new village leaders and health workers. 3. Examine the relationship between family planing rumors and family planning practices. The materials for this study were drawn from the two different sets of data gathered in July and Octorber 1977 respectivily by Center for Population ＆ family Planning, Yon sei University. One is current family planning practice among eligible women reaiding in 4 Myuns in Kwang Wha country and the other is Survey on Rumor on family planning method heard by new village leaders and health workers in the four myuns. The four Myuns were divided into 60 small areas. Current family planning practice rate in each small area and as a whole were calculated. The unit of analysis in this study was not the indviduel person but the 55 small areas. Percentage, average, F-Test t-test and a coefficient of correlation were used for statistical analysis. Results of this study could be summarized as follows: 1. Rumors by different method of contraception: Medical complications, gastro-intestinal disorders, and difficulty in usage one most prevalent rumors about oral pills. Around 49% -77% of the 55 areas were often heard and the most frequent rumor was related medical complications of oral pills. Rumors on medical complications and incomplete effect of intrauterines as contraceptive were heard 51-66% of the 55 small areas. Rumors that vasectomy resulted in family problems, for instance infiedelity of spouse were often heard to 44% of the 55 small areas. 2. Rumors by socio-economic and demographic characteristic of new village leader and health workers: Among the demographic characteristics such as sex, age and sex composition of children, sex and age differentials in frequency of rumors heard more observed, Female new village health workers have heard more frequently than male new village leader. (t = 7.137, p> 0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) The Younger age group less than 40 years of age have heard rumors of than the group over 40 years old. (t = 7.18, p>0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) However, it was not observable that a consistent sex and age differentials in frequency of rumors heard of each contraceptive mettled, But, more female new village health works heard of rumors about intrauterine device than male new village leaders. (t = 0.497, p> 0.01, d.f. = 53, a coefficient of correlatin 0.32, p>0.01) 3. It was found that there was no statistically significant relationship between the frequency of rumors heard and current family planning practices on the whole, However, frequency of rumors heard about vasectomy appeared to have a positive relationship with current practice of vasectomy. A rather consistent pattern of relationship between“requency of rumors heard”and current family practice rate was demonstrated of 10 graphes which showed the relation between the two variagles. The current family planning practice rate in the“never heard”group and “frequently heard”group was equally lower than that in“often heard”group. The relatively consistent ∩ pattern of relationship needs to be farther investigated, for this pattern is different from the relationship that has been assumed to exist between these two variables.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.365-368
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• 2002

Background: Coronary artery bypass grafting(CABG) imposes large amount of medical costs, which are greatly affected by the surgical approach, quality of perioperative care and associated co-morbidities. Recently, off-pump CABG(OPCAB) has been introduced and performed with increasing frequency. To evaluate the efficacy of OPCAB in view of financial impact, we analyzed the costs and medical resources of OPCAB and compared with conventional CABG. Material and Method: From January 1998 to July 1999, 184 patients underwent CABG operation; 111 patients with OPCAB(group I) and 73 patients with conventional CABG(group II). We prospectively collected clinical data including risk factors and retrospectively reviewed the hospital resources. Result: Preoperative parameters including risk factors, postoperative mortality, morbidity and length of hospital stay were not different between the two groups, Duration of stay in the intensive care unit(ICU) (51.3 vs 128.3 hours, p<0.01) and ventilator, support time(14.9 vs 56.2 hours, p<0.01) were significantly shorter in the OPCAB group. Total hospital coats were 17,220,000 add 21,250,000(Korean Won) in group I and II, respectively(p<0.01). There were significant differences in operation fee, costs for operative materials, transfusion and diagnostic radiology between two groups. In group I, all the resources except diagnostic radiology were significantly decreased compared with group II. Conclusion: OPCAB has a beneficial effect on hospital charge and resource utilization. Shorter duration of the ICU stay and ventilatory support time may reduce the total hospital costs.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.532-539
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• 1993

Background: Physician's estimates of patient survival often influence clinical decisions, especially those near the end of life. In addition. clinical decisions frequently reflect trade-offs between morbidity and length of survival. As a result, accurate estimates of survival can be extremely useful in clinical decision. When the episode of acute respiratory failure in chronic obstructive lung disease, evaluation of the severity of the condition and short term prognosis is difficulit based on the available clinical or paraclinical data at the time of admission. Method: In this study, we performed a retrospective study in Chung Ang University Hospital, 74 patients (51 males, 23 females), who were hospitalized with chronic obstructive lung disease with acute respiratory failure from 1980 to 1992. We evaluated these patients to determine lung prognostic factors at time of admission in the Intensive Care Unit (ICU) that predict short term survival, and to determine the possible application of the Simplified Acute Phsiology Score (SAPS) to this population, All patients were treated with similar regimen during the hospitalization. Results: The results were as follows: 1) Hospital mortality was 34%(25/74 patients) and surival rate was 66%(49/74 patients) in COPD with acute respiratory failure. The prognosis of the older age was much poorer than those of the young age. 2) There was no difference in mortality according to the results of basal pulmonary test and arterial blood gas analysis. 3) The SAPS at admission was higher in those patients who expired(10.8) than the survived(6.5), and there was positive correlation between SAPS and mortality (r=0.91, p<0.05). 4) Prognostic factors in acute respiratory failure complicating COPD which were identifiable at time of admission to the ICU were as follows: cachexia, encephalopathy, serum creatinine and phosphate. Conclusion: In conclusion, the SAPS might have a good prognostic value for determination of short term survival among chronic obstructive lung disease with acute respiratory failure.

• Neonatal Medicine
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• v.18 no.1
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• pp.89-95
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• 2011

Purpose: Hypernatremia most frequently occurs in the immature newborn and be severe in association with intraventricular hemorrhage (IVH). This study examined the frequency, onset and risk factors of hypernatremia, and the relationship between hypernatremia and IVH in very low birth weight (VLBW; <1,250 g) infants. Methods: We retrospectively reviewed the medical records of 55 VLBW infants admitted between January 2006 and December 2009 to the neonatal intensive care unit of Wonkwang University Hospital and who survived over 7 days. Serum sodium concentration, sodium intake, fluid and weight loss, as suggested risk factors of hypernatremia, and the incidence of IVH were evaluated. The infants were divided into a hypernatremia group (${\geq}$150 mEq/L) and nonhypernatremia group, and were compared. Results: Incidence of hypernatremia in the VLBW infants was 52.7%, and mean starting time of hypernatremia was 2.8${\pm}$1.3 days. There were no differences in the sodium and fluid intake between the two groups. Weight loss at day 3 after birth was significantly higher in the hypernatremia compared to the nonhypernatremia group (P<0.05); thereafter weight loss was non-significantly higher. The incidence of IVH in VLBW infants was 38.2%, and the difference between the two groups was not significant. Conclusion: Hypernatremia occurs commonly in VLBW infants and is most commonly caused by weight loss in the early days after birth. Incidence of IVH is not likely influenced by hypernatremia with marginally elevated sodium concentration.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1330-1336
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• 2005

Purpose : It has been suggested that changes in cerebral blood flow by ventilator care could be a risk factor in periventricular leukomalacia(PVL) and severe periventricular-intraventricular hemorrhage(PV-IVH). The study aims to assess the relationship between perinatal clinical events, including ventilator care, and the development of PVL and severe PV-IVH; especially, whether ventilator care could be causers of PVL and severe PV-IVH as an individual risk factor. Methods : Among 255 very low birth weight infants who survived in the Fatima neonatal intensive care unit from January 1999 to December 2003, 15 infants with PVL and eight infants with severe PV-IVH were classified as a study group, while 231 infants were enrolled as a control group. The analysis was performed retrospectively with medical records. Results : Twenty four infants were diagnosed with PVL or severe PV-IVH. Asphyxia, recurrent apnea, sepsis, acidosis and ventilator care were significantly increased in the PVL goup. Asphyxia, recurrent apnea, RDS, acidosis and ventilator care were significantly increased in the severe PV-IVH group. Conclusion : Infants with PVL or severe PV-IVH may have multiple perinatal risk factors including asphyxia, recurrent apnea, sepsis, acidosis, RDS and ventilator care. Because most patients with ventilator care have multiple perinatal risk factors, ventilator care does not cause PVL and severe PV-IVH independently. Therefore, incidences of PVL and severe PV-IVH can be decreased by not only gentle ventilation, but also more professional antenatal care.

• Clinical and Experimental Pediatrics
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• v.46 no.1
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• pp.24-32
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• 2003

Purpose : Nosocomial infection with Staphylococcus aureus, especially methicillin resistant S. aureus, has become a serious concern in the neonatal intensive care unit. The aim of this study is to investigate the virulence factors, and the relationship between the antibiotic resistance and the associated genes of Staphylococcus aureus isolated from nasal cavity of neonates. Methods : Fifty one isolates of S. aureus were obtained from nasal swab taken in 28 neonates in the NICU and nursery of Pusan National University Hospital between February and May, 2001. They were tested in regard to antibiotic susceptibility, coagulase test and typing, plasmid DNA profile, as well as reactivity to enterotoxin A-E(sea, seb, sec, sed, see) genes and toxic shock syndrome toxin-1(tst) gene by polymerase chain reaction(PCR). Associated genes such as mecA, mecR1, mecI, and femA were also determined by PCR. The origin of MRSA strains was assessed using DNA fingerprinting by arbitrarily-primed polymerase chain reaction(AP-PCR). Results : Twenty three(45.1%) and six(11.8%) isolates were resistant to oxacillin and vancomycin respectively. Multidrug resistance to three or more of the antibiotics tested was observed in 51.0% of the isolates. Forty two isolates were coagulase positive and twenty two isolates had mecA gene. Sixteen isolates had both mecA and femA genes and had type I-III plasmids. 64.7% of isolates carried sec gene, and 80.4% carried tst gene. DNA fingerprinting by AP-PCR for 12 MRSA strains showed 10 distinct patterns, suggesting different origins. Conclusion : We confirmed that the prevalence of nasal carriage of S. aureus and the incidence of antimicrobial-resistant S. aureus, especially vancomycin resistance, is very high in neonates who were admitted in NICU and nursery. It is possible that these pathogens are responsible for serious nosocomial infections in neonates. The need for improved surveillance and continuous control of pathogens is emphasized.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.168-177
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• 2017

Purpose: The purpose of this study was to analyze the clinical features and risk factors of invasive infections caused by Lactobacillus spp. and Saccharomyces spp., components of commercially available probiotics. Methods: We analyzed demographic and clinical data from children ${\leq}18$ years of age with an invasive infection caused by Lactobacillus spp. or Saccharomyces spp. at the Asan Medical Center Children's Hospital from January 1998 to June 2016. Probiotic consumption data were also analyzed. Results: During the study period, a total of 24 episodes of invasive infections were caused by Lactobacillus spp. (n=16) and Saccharomyces cerevisiae (n=8). Along with the increase of probiotic use (755,594 [days/1,000 patient-admission days] in 2001 to 2005, 1,444,066 in 2006 to 2010, and 6,904,736 in 2011 to 2016), the incidence of probiotic-associated invasive infection increased ($R^2=0.70$). The median age of the patients was 1.8 years (range, 2 months to 17 years), and most of them had underlying medical conditions. The 30-day mortality rate was 20.8% (5/24), and 11 (45.8%) of these patients resulted from a severe invasive infection. We determined the risk factors for invasive infection to be: previous intensive care unit stay (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.5 to 6.1] and the presence of a central venous catheter (OR, 2.2; 95% CI, 1.2 to 4.3). Conclusions: Although the probiotic-associated invasive infections rarely occurred in children, the incidence has increased along with probiotic pressure. Judicious use of probiotics is mandatory, especially in young children with underlying medical conditions and continuous surveillance will be needed to minimize the safety concerns.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.1
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• pp.66-75
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• 2014

This study aims to understand environmental factors that determine spatial distribution of macrozoobenthic community in the southern area (ca 100-500 m depth) of East Sea, Korea, known as a candidate site for carbon storage under the seabed. From sixteen locations sampled in the summer of 2012, a total of 158 species were identified, showing density of $843indiv/m^2$ and biomass of $26.2g\;WW/m^2$, with increasing faunal density towards biologically higher diverse locations. Principal component analysis showed that a total of 33 environmental parameters were reduced to three principal components (PC), indicating sediment, bottom water, and depth, respectively. As sand content was increasing, number of species increased but biomass decreased. Six dominant species including two bivalve species favored high concentrations of ${\Omega}$ aragonite and ${\Omega}$ calcite, indicating that the corresponding species can be severely damaged by ocean acidification or $CO_2$ effluent. Cluaster analysis based on more than 1% density dominant species classified the entire study area into four faunal assemblage (location groups), which were delineated by characteristic species, including (A) Ampelisca miharaensis, (B) Edwardsioides japonica, (C) Maldane cristata, (D) Spiophanes kroeyeri, and clearly separated in terms of geography, bottom water and sediment environment. Overall, a discriminant function model was developed to predict four faunal assemblages from five simply-measured environmental variables (depth, sand content in sediment, temperature, salinity and pH in bottom water) with 100% accuracy, implying that benthic faunal assemablages are closed linked to certain combinations of abiotic factors.