• Journal of Chest Surgery
• /
• v.38 no.3 s.248
• /
• pp.181-190
• /
• 2005

The results of biventricular repair for double outlet right ventricle have been improved in recent series. We studied the surgical and long term results for total correction of double outlet right ventricle by the type of ventricular septal defect. Material and Method: Between November 1979 and December 2003, 126 patients had biventricular repair for double outlet right ventricle. The mean age was 1.8 years (range 1$\~$44) and 86 patients ($68.3\%$) were male. We classified and studied this disease by the type of VSD. Result: The locations of VSD were subaortic in 79 ($62.7\%$), subpulmonary in 17 ($13.5\%$), doubly committed in 16 ($12.7\%$) and noncommitted in 14 ($11.1\%$). 28 patients had palliative operation before total correction and the mean interval to total correction was 41.0$\pm$45.1 months. The methods of total correction were intraventricular baffling in 37 ($29.4\%$), intraventricular baffling with patch enlargement of right ventricular outflow tract in 49 ($38.9\%$), intraventricular baffling with Rastelli procedure in 15 ($11.9\%$), arterial switch operation in 8 ($6.3\%$) and REV procedure in 4 ($3.2\%$), etc. Hospital mortality rate was $10.3\%$ (13 patients) and 25 reoperations were performed in 24 patients ($19.0\%$). The risk factors for hospital mortality and reoperation were cardiopulmonary bypass time (p=0.020) and previous palliative operation (p=0.013), respectively. Follow up was possible in 98 patients and mean follow up period was 118.9$\pm$70.7 months. The percent survival and survival for freedom from reoperation at 15 years were $82.5\%$ and $66.7\%$, respectively. The survival rate was significantly lower (p=0.003) in transposition of great artery type and remote type than in simple ventricular septal defect type and tetralogy of Fallot type, but there was no statistical differences in survival rate for freedom from reoperation. Conclusion: It is thought to be that acceptible surgical and long term results can be obtained with application of appropriate methods of repair for double outlet right ventricle.

• Journal of Environmental Policy
• /
• v.9 no.2
• /
• pp.185-205
• /
• 2010

Climate change vulnerability assessment based on local conditions is a prerequisite for establishment of climate change adaptation policies. While some studies have developed a methodology for vulnerability assessment at the national level using statistical data, few attempts, whether domestic or overseas, have been made to develop methods for local vulnerability assessments that are easily applicable to a single city. Accordingly, the objective of this study was to develop a conceptual framework for climate change vulnerability, and then develop a general methodology for assessment at the regional level applied to a single coastal city, Mokpo, in Jeolla province, Korea. We followed the conceptual framework of climate change vulnerability proposed by the IPCC (1996) which consists of "climate exposure," "systemic sensitivity," and "systemic adaptive capacity." "Climate exposure" was designated as sea level rises of 1, 2, 3, 4, and 5 meter(s), allowing for a simple scenario for sea level rises. Should more complex forecasts of sea level rises be required later, the methodology developed herein can be easily scaled and transferred to other projects. Mokpo was chosen as a seaside city on the southwest coast of Korea, where all cities have experienced rising sea levels. Mokpo has experienced the largest sea level increases of all, and is a region where abnormal high tide events have become a significant threat; especially subsequent to the construction of an estuary dam and breakwaters. Sensitivity to sea level rises was measured by the percentage of flooded area for each administrative region within Mokpo evaluated via simulations using GIS techniques. Population density, particularly that of senior citizens, was also factored in. Adaptive capacity was considered from both the "hardware" and "software" aspects. "Hardware" adaptive capacity was incorporated by considering the presence (or lack thereof) of breakwaters and seawalls, as well as their height. "Software" adaptive capacity was measured using a survey method. The survey questionnaire included economic status, awareness of climate change impact and adaptation, governance, and policy, and was distributed to 75 governmental officials working for Mokpo. Vulnerability to sea level rises was assessed by subtracting adaptive capacity from the sensitivity index. Application of the methodology to Mokpo indicated vulnerability was high for seven out of 20 administrative districts. The results of our methodology provides significant policy implications for the development of climate change adaptation policy as follows: 1) regions with high priority for climate change adaptation measures can be selected through a correlation diagram between vulnerabilities and records of previous flood damage, and 2) after review of existing short, mid, and long-term plans or projects in high priority areas, appropriate adaptation measures can be taken as per this study. Future studies should focus on expanding analysis of climate change exposure from sea level rises to other adverse climate related events, including heat waves, torrential rain, and drought etc.

• 대한공업교육학회지
• /
• v.40 no.1
• /
• pp.142-162
• /
• 2015

The purpose of this study are to provide the basic data materials and implementations for successful performance of electric-work field representatives of South Korean firms by identifying their roles and competency and examining their educational need. For this research purposes, three phased analysis was followed on: (1) the roles of electric-work field representatives, (2) competency of electric-work field representatives and (3) educational need for their competency. This research method was to conduct a focus group interview for 10 expert field representatives along with survey. The collected data materials were processed by MS Excel and SPSS 21.0 for statistical analysis including average, standard deviation and other basic statistics; the gap in awareness of field representatives; and need values. For the needs analysis, the difference between significance of field representatives' competency and current status was examined by t test. And the awareness gap between competency importance and current status was identified based on the Borich equation. The Locus for Focus model was employed herein to identify the kinds of competency with high importance and high inconsistency to prioritize. As a result, this research has found as follows: first, the roles of field representatives were found to be in 13 different kinds of roles. Second, electric-work field representatives were found to need to have 16 different skills. Third, regarding the 16 abilities, the gap between current status and significance was analyzed herein. The results showed statistically significant differences in all cases. The Borich needs analysis found the first required ability was communication ability followed by power of execution, conflict management ability, analytical thinking and time management ability. Also, the results of Locus for Focus model analysis displayed that the first quadrant(HH) included 7 highly-demanded abilities of communication ability, analytical thinking, decision making ability, specialty, time management ability, power of execution and drive for work implementation. The top-priority group was found to have 5 items of communication ability, analytical thinking, time management ability, power of execution and drive for work implementation which were commonly seen in the Locus for Focus model outcomes. Based on these findings, this research could identify the roles and competency of electric-work field representatives and provide the basic data materials applicable to future personal management of electricity companies including recruitment, division of work, job description, evaluation, etc. Also this research offered guidelines on demanded abilities in the field and where to place priority. The kinds of abilities with high educational demand as found in this research must be considered in designing educational programs for the competency building of field representatives. This research is expected to provide useful information in developing such educational programs for field representatives.

• Journal of Intelligence and Information Systems
• /
• v.20 no.4
• /
• pp.121-139
• /
• 2014

Predicting corporate failure has been an important topic in accounting and finance. The costs associated with bankruptcy are high, so the accuracy of bankruptcy prediction is greatly important for financial institutions. Lots of researchers have dealt with the topic associated with bankruptcy prediction in the past three decades. The current research attempts to use ensemble models for improving the performance of bankruptcy prediction. Ensemble classification is to combine individually trained classifiers in order to gain more accurate prediction than individual models. Ensemble techniques are shown to be very useful for improving the generalization ability of the classifier. Bagging is the most commonly used methods for constructing ensemble classifiers. In bagging, the different training data subsets are randomly drawn with replacement from the original training dataset. Base classifiers are trained on the different bootstrap samples. Instance selection is to select critical instances while deleting and removing irrelevant and harmful instances from the original set. Instance selection and bagging are quite well known in data mining. However, few studies have dealt with the integration of instance selection and bagging. This study proposes an improved bagging ensemble based on instance selection using genetic algorithms (GA) for improving the performance of SVM. GA is an efficient optimization procedure based on the theory of natural selection and evolution. GA uses the idea of survival of the fittest by progressively accepting better solutions to the problems. GA searches by maintaining a population of solutions from which better solutions are created rather than making incremental changes to a single solution to the problem. The initial solution population is generated randomly and evolves into the next generation by genetic operators such as selection, crossover and mutation. The solutions coded by strings are evaluated by the fitness function. The proposed model consists of two phases: GA based Instance Selection and Instance based Bagging. In the first phase, GA is used to select optimal instance subset that is used as input data of bagging model. In this study, the chromosome is encoded as a form of binary string for the instance subset. In this phase, the population size was set to 100 while maximum number of generations was set to 150. We set the crossover rate and mutation rate to 0.7 and 0.1 respectively. We used the prediction accuracy of model as the fitness function of GA. SVM model is trained on training data set using the selected instance subset. The prediction accuracy of SVM model over test data set is used as fitness value in order to avoid overfitting. In the second phase, we used the optimal instance subset selected in the first phase as input data of bagging model. We used SVM model as base classifier for bagging ensemble. The majority voting scheme was used as a combining method in this study. This study applies the proposed model to the bankruptcy prediction problem using a real data set from Korean companies. The research data used in this study contains 1832 externally non-audited firms which filed for bankruptcy (916 cases) and non-bankruptcy (916 cases). Financial ratios categorized as stability, profitability, growth, activity and cash flow were investigated through literature review and basic statistical methods and we selected 8 financial ratios as the final input variables. We separated the whole data into three subsets as training, test and validation data set. In this study, we compared the proposed model with several comparative models including the simple individual SVM model, the simple bagging model and the instance selection based SVM model. The McNemar tests were used to examine whether the proposed model significantly outperforms the other models. The experimental results show that the proposed model outperforms the other models.

• Journal of Music and Human Behavior
• /
• v.1 no.1
• /
• pp.11-32
• /
• 2004

According to Edwin Gordon(1987, 1997, 2003), music aptitude is a product of interaction of innate potential and early environmental experiences. He referred to music aptitude of children up to nine years of age as developmental music aptitude which fluctuates due to musical environment. Music aptitude stabilizes at age nine, and the music aptitude after age nine is called "stabilized music aptitude". This research is to examine Gorden's hypothesis that the younger a child receives music education, the higher music aptitude. Also, this research is to experiment the effect of Audiation activities developed in Audie Music Curriculum on music aptitude. The researcher and another Audie teacher as a co-teacher guided children together for 30 minutes once a week. The pedagogy guidelines for informal guidance in music learning theory were kept throughout the classes. Also, Audie's teaching method which had been developed for Korean Kindergarten educational environment was also applied. Five-year-old subjects in Experimental group 1 experienced the Audie Music Curriculum of one year; five-year-old subjects in Experimental group 2 experienced it for two years. Primary Measures of Music Audiation was administered three times during their last year of Kindergarten. Subjects in the Control groups, one examined at the beginning and the other at the end of their last year in Kindergarten, received no Audie instruction. There was no significant difference in tonal aptitude, but there was significant difference in rhythmic aptitude(p< .05) among the experiemental groups. Because both Experimental groups showed statistical significance (p< .001) in the music aptitude increase during their academic years, the significant differences of the year-end music aptitude between control group and experimental groups were the expected result.

• Korean Journal of Remote Sensing
• /
• v.34 no.3
• /
• pp.451-463
• /
• 2018

The empirical/statistical models to estimate the ground Particulate Matter ($PM_{2.5}$) concentration from Geostationary Ocean Color Imager (GOCI) Aerosol Optical Depth (AOD) product were developed and analyzed for the period of 2015 in Seoul, South Korea. In the model construction of AOD-$PM_{2.5}$, two vertical correction methods using the planetary boundary layer height and the vertical ratio of aerosol, and humidity correction method using the hygroscopic growth factor were applied to respective models. The vertical correction for AOD and humidity correction for $PM_{2.5}$ concentration played an important role in improving accuracy of overall estimation. The multiple linear regression (MLR) models with additional meteorological factors (wind speed, visibility, and air temperature) affecting AOD and $PM_{2.5}$ relationships were constructed for the whole year and each season. As a result, determination coefficients of MLR models were significantly increased, compared to those of empirical models. In this study, we analyzed the seasonal, monthly and diurnal characteristics of AOD-$PM_{2.5}$model. when the MLR model is seasonally constructed, underestimation tendency in high $PM_{2.5}$ cases for the whole year were improved. The monthly and diurnal patterns of observed $PM_{2.5}$ and estimated $PM_{2.5}$ were similar. The results of this study, which estimates surface $PM_{2.5}$ concentration using geostationary satellite AOD, are expected to be applicable to the future GK-2A and GK-2B.

• Korean Security Journal
• /
• no.13
• /
• pp.351-382
• /
• 2007

This study seeks to analyze various aspects of women's fear of sexual crime committed against them within the Seoul metropolitan subway system, which takes center stage in public transportation today in Korea; that is, among different kinds of fear of crime, women's fear of sexual crime is empirically examined, and it is expected that the results of this study shall serve as an important basis for future policy-making, so that the fear of sexual crime against women in the subway system could be reduced. To the end, this study aims first, to investigate the real picture of women's using the subway and their attire, second, to look into the amount of information on such crime obtained and the level of its awareness, third, to analyze the characteristics of the fear of sexual crime in the subway system, and lastly, to empirically examine the relationship between women's regular women's regular attire/their level of information on such crime obtained and their fear of sexual crime. As a quantitative research method to discover facts, this study utilizes reality-analyztical and technical research methods, and for its final statistical analysis, uses questionnaire answered and returned by 509 women, out of a total of 520 female commuters on the Seoul metropolitan subway system who had originally been requested to participate in the survey. The result of this study demonstrates that the level of women's fear of sexual crime on the subway is relatively high. In detail, the higher their monthly income is, the more fearful women feel on the subway; it has also been found that women living in housing they own or in leased housing on deposits (Jeonse) fear sexual crime on the subway more than those living in the other forms of housing. However, the level of fear has been found to be low for those types of sexual crime judged to be relatively unlikely to be committed. Lastly the result of the relationship between women's regular attire/their level of information on such crime obtained and their fear of sexual crime is relatively high and very effective.

• Investigative Magnetic Resonance Imaging
• /
• v.8 no.1
• /
• pp.24-31
• /
• 2004

Purpose : To know the differences of proton MR spectroscopic features between recurrent rectal cancer and fibrosis in post-operative period, and to evaluate the possibility to discriminate recurrent rectal cancer from post-operative fibrosis by analysis of proton MR spectra. Materials and Methods : We evaluated the proton MR spectra from 25 soft tissue masses in perirectal area that developed in post-operative period after operation for the resection of rectal cancer. Our series included 11 cases of recurrent rectal cancer and 14 of fibrotic mass. All cases of recurrent rectal cancer and post-operative fibrosis were confirmed by biopsy. We evaluated the spectra with an attention to the differences of pattern of the curves between recurrent rectal cancer and post-operative fibrosis. The ratio of peak area of all peaks at 1.6-4.1ppm to lipid (0.9-1.6ppm) [P (1.6-4.1ppm/P (0.9-1.6ppm)] was calculated in recurrent rectal cancer and post-operative fibrosis groups, and compared the results between these groups. We also evaluated the sensitivity and specificity for discriminating recurrent rectal cancer from post-operative fibrosis by analysis of $^1H-MRS$. Results : Proton MR spectra of post-operative fibrosis showed significantly diminished amount of lipids compared with that of recurrent rectal cancer. The ratio of P (1.6-4.1ppm)/P (0.9-1.6ppm) in post-operative fibrosis was much higher than that of recurrent rectal cancer with statistical significance (p < .05) due to decreased peak area of lipids. Mean (standard deviations of P (1.6-4.1ppm)/P (0.9-1.6ppm) in post-operative fibrosis and recurrent rectal cancer group were $2.71{\pm}1.48\;and\;0.29{\pm}0.11$, respectively. With a cut-off value of 0.6 for discriminating recurrent rectal cancer from post-operative fibrosis, both the sensitivity and specificity were $100\%$ (11/11, and 14/14). Conclusion : Recurrent rectal cancer and post-operative fibrosis can be distinguished from each other by analysis of proton MR spectroscopic features, and $^1H-MRS$ can be a new method for differential diagnosis between recurrent rectal cancer and post-operative fibrosis.

• Investigative Magnetic Resonance Imaging
• /
• v.1 no.1
• /
• pp.114-118
• /
• 1997

Purpose: Functional MR imaging is the method of demonstrating changes in regional cerebral blood flow produced by sensory, motor, and any other tasks. Functional MR of visual cortex is performed as a patient stares a photic stimulation, so adaptable photic stimulation is necessary. The purpose of this study is to evaluate whether the size of photic stimulator can affect the degree of visual cortex activation. Materials and Methods: Functional MR imaging was performed in 5 volunteers with normal visual acuity. Photic stimulator was made by 39 light-emitting diodes on a plate, operating at 8Hz. The sizes of photic stimulator were full field, half field and focal central field. The MR imager was Siemens 1.5-T Magnetom Vision system, using standard head coil. Functional MRI utilized EPI sequence (TR/TE= 1.0/51. Omsec, matrix $No.=98{\times}128$, slice thickness=8mm) with 3sets of 6 imaging during stimulation and 6 imaging during rest, all 36 scannings were obtained. Activation images were obtained using postprocessing software(statistical analysis by Z-score), and these images were combined with T-1 weighted anatomical images. The activated signals were quantified by numbering the activated pixels, and activation a index was obtained by dividing the pixel number of each stimulator size with the sum of the pixel number of 3 study using 3 kinds of stimulators. The correlation between the activation index and the stimulator size was analysed. Results: Mean increase of signal intensities on the activation area using full field photic stimulator was about 9.6%. The activation index was greatest on full field, second on half field and smallest on focal central field in 4. The index of half field was greater than that of full field in 1. The ranges of activation index were full field 43-73%(mean 55%), half field 22-40 %(mean 32%), and focal central field 5-24%(mean 13%). Conclusion: The degree of visual cortex activation increases with the size of photic stimulator.

• Journal of Chest Surgery
• /
• v.39 no.8 s.265
• /
• pp.619-625
• /
• 2006

Background: Peripheral arterial disease is frequently accompanied with systemic arteriosclerosis and more than half of the cause of deaths is due to the development of coronary arterial disease. Moreover, it is known that the most frequent cause of death after a bypass surgery of chronic arterial obstruction is heart related complications. Especially in patients with atherosclerotic arterial obstruction in the lower extremities who had no history of heart disease or had no presenting symptoms of ischemic heart disease showed a high rate of postoperative mortality and for this reason we suggest preoperative evaluation in these patients to evaluate whether or not coronary arterial disease is accompanied. Material and Method: Since Feb. 2001 to Oct. 2004, we analyzed 52 patients who were operated on for atherosclerotic arterial obstruction in the lower extremities, with the exception of patients with a past history of heart disease or symptoms of ischemic heart disease. They underwent on the same day a coronary and femoral angiography for evaluation of accompanying coronary arterial disease. Of among these patients, we compared those who received bypass surgery of the arteries of the peripheral extremities alone to those who underwent combined coronary artery bypass surgery. Result: 63% of the reported cases of atherosclerotic arterial obstruction in the lower extremities were accompanied with coronary arterial disease. Old age, hypertension, diabetes mellitus, smoking, and hypercholesterolemia are known risk factors for arteriosclerosis and of these, only old age and hypertension had statistically significance in patients with severe atherosclerotic arterial obstruction in the lower extremities accompanied with coronary arterial disease. Diabetes, smoking, and hypercholesterolemia showed no statistical significance in this group. With the increase in severity of the range and the degree of atherosclerotic arterial obstruction, coronary arterial disease is frequently accompanied and its severity also increased. Patients who received both peripheral artery and coronary artery bypass surgery showed no difference in the period of hospitalization and ICU stay period compared with patients who received bypass surgery of the arteries of the lower extremities alone. Conclusion: Patients with atherosclerotic arterial obstruction in the lower extremities without symptoms of ischem to evaluate coronary arterial disease for active treatment, especially in the patients with old age, hypertension and high AVD scores.