• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.247-255
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• 2006

The purpose of this study was to investigate the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. The subjects of the investigation consisted of 120 third grade students attending high school in K city of Kyunggi province. For this study, questionnaire relevant to the subject of chemical reaction rates and chemical equilibrium was developed and the answers were analyzed. As a result of the study, a large percentage of high school students answered questions on reaction rates correctly, but only a small percentage of the students could give explanations. Many high school students answered questions on the rates of forward reactions correctly, but not the questions on the rates of reverse reactions. For the concepts on chemical equilibrium, many high school students gave correct answers when faced with equilibrium questions that only required the understanding of one side of the reaction. But the students could not answer the questions requiring understanding of both forward and reverse reactions as well. Overall, there was a little high correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. Especially, high school students with little understanding of reverse reaction rates did not understand that chemical equilibrium is a dynamic equilibrium. Also, high school students with little understanding of the collision mechanism regarding chemical reaction rates did not understand the effect of concentration and catalyst factors on chemical equilibrium. And the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium related to concentration and catalyst factors was low. In conclusion, the formation of scientific concepts on chemical reactions rates can decrease misconceptions on chemical equilibrium. Also the teaching-learning method limited to one side of a reaction can cause difficulty in forming the concepts on chemical dynamic equilibrium. Therefore, the development of a teaching-learning method which covers both the forward and reverse reactions can be effective in helping students form the concepts on chemical equilibrium.

• Journal of Hospice and Palliative Care
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• v.5 no.2
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• pp.146-154
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• 2002

Purpose : Death due to cancer has been continuously increasing, therefore cancer is the first in the cause of death now. A national policy for the elevation of medical costs in cancer patients is necessary, therefore, we searched for the medical costs and its related factors in terminal cancer patients for the effective reduction of the medical costs. Methods : We reviewed the medical records of 259 hospitalized terminal cancer patients who had died during the period of July 1, 2000 to June 30, 2002. History of cancer included type of cancer, type of past treatment, existence of metastasis. Clinical manifestation was examined and medical costs on last admission was categorized based on the account of charges of the department of patient affair on the last hospitalization. For analysis of factors related with medical costs, ANOVA was used. Results : Of the 259 patients, the number of male was 135 cases (52.1%), and the female, 124 cases (47.9%). The most frequent type of cancer was stomach (21.9%) cancer. Of the clinical manifestation, anorexia (87.6%) was the most frequent manifestation. Total medical costs was 740,628,045won, the mean costs was $285,968{\pm}3,070,272won$. The frequent category of medical costs was injection (32.0%), medical accommodation (27.9%), examination (14.0%), in order. The only factor related with mean medical costs was pain (P<0.05). Conclusion : If unnecessary injection of opioid analgesics is reduced, hospice care at home is activated and excessive examination is reduced In terminal cancer inpatients, it will be possible to reduce the medical costs in terminal cancer patients more effectively.

• Journal of Hospice and Palliative Care
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• v.19 no.3
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• pp.249-255
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• 2016

Purpose: Up to 90% of pancreatic cancer patients suffer from neuropathic pain. In a palliative care setting, pain control in pancreatic cancer patient is one of the major goals. Ketamine is a N-methyl-D-aspartate (NMDA) receptor antagonist, effective in neuropathic pain. Additionally, there have been studies about the opioid sparing effect of ketamine. This study was held in the palliative care unit among pancreatic cancer patients to determine the factors related to ketamine use and the opioid sparing effect. Methods: The medical records of pancreatic cancer patients admitted to St. Mary's hospital palliative care unit between January, 2013 and December, 2014 were reviewed. Patients were divided into 2 categories according to ketamine use. Also, opioid use before and after ketamine use was compared in the ketamine group. Results: Compared to the non-ketamine use group, patients in the ketamine group required a higher dose of opioid. The total opioid dose, daily opioid dose, number of daily rescue medications, and daily average rescue dose were statistically significantly higher in the ketamine group. The opioid requirement was increased after ketamine administration. Conclusion: In this retrospective study, ketamine was frequently considered in patients with severe pain, requiring higher amount of opioid. Studies about palliative use of ketamine in a larger number of patients with diverse types of cancer pain are required in the future.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.320-328
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• 2016

This study was conducted to provide important basic information about effective management of the marine environment at major inflow streams in Lake Andong and Lake Imha. The investigation was conducted 8 times from May, 2015 (AD1, AD2, IH1, IH2) to September, 2016 (AD3, AD4, IH3, IH4), and 8 surveyed sites were selected at Lake Andong (4 sites) and Lake Imha (4 sites). The inquiry identified 114 species, $59,913.7inds.\;m^{-2}$ in Lake Andong and 112 species, $39,038.4inds.\;m^{-2}$ in Lake Imha. The results indicate that the number of species and individuals in Lake Andong is more than that in Lake Imha, because Lake Andong has a variety of riparian vegetation and a richness of organic materials. Community analysis at Lake Imha revealed a dominant index of 0.57 (${\pm}0.18$), a diversity index of 2.87 (${\pm}0.31$), an evenness index of 0.73 (${\pm}0.04$), and a richness index of 4.17 (${\pm}0.71$). The results of functional feeding group analysis showed that a high proportion of species and individuals are gathering collectors. The results of functional habitat group analysis showed that a high proportion of species and individuals are clingers. The result of a physico-chemical water assay and dissolved oxygen and electric conductivity tests revealed that these measures increased when the water temperature decreased. The result of Pearson's correlation analysis by biological factors and physico-chemical factors showed that species and electric conductivity are highly correlated with one another. Major inflow streams of Lake Andong and Lake Imha were exposed to various point pollution sources and non-point pollution sources. This implies a necessity for continuous monitoring of the aquatic ecosystems in order to effect systematic water quality management of Lake Andong and Lake Imha.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.2
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• pp.29-48
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• 2000

This study was designed to diagnose the correlations between health promotion behavior and primary school students' demographic characteristics and their self-concept, and also this study was aimed at representing the basic data of proper instruction method and school health program with the respective to primary school students' health promotion behavior through the above things. For this, author selected as 5th, 6th graders, 400 persons at 5 elementary schools located on Kyonggi province. This data utilized ANOVA, multiple regression analysis and correlation analysis by SPSS program. The findings of this study were as follows; First, there showed meaningful differences concerning their health promotion behavior according to students' demographic traits. There were a birth date, living standard, domestic environments etc. as a factors which influenced on their health promotion behavior. With this, from ex-past-facto verification for these variable factors, as their birth date was faster, living standard was higher, domestic environments was better, as their health promotion behavior was more promotive. Second, students' health promotion behavior marked 3.61 among total 5 paint with the respective to its fulfillment degree, their self-concept marked 3.45 among total 5 paint. Their mental health promotion behavior marked 3.71 with the respective to inferior category of health promotion behavior, which was the highest score. In the other hands, their physical health promotion behavior marked 3.71, social health promotion behavior marked 3.45. contrary the disease prevention, first-aid & safety, oral health, health & nutrition(P>.05). Third, there show meaningful difference, in the level of p-value <.001 with the respective to the correlations between primary school students' health promotion behavior and their self-concept, more their self-concept was positive, more their more their whole health promotion behavior(r=.479), the fulfillment degree of physical health promotion behavior(r=.384), mental health promotion behavior(r=.543), social health promotion behavior(r=.372) were high. Fourth, with the respective to the results of difference verification concerning their fulfillment degree of health promotion behavior according to the upper, middle, inferior group of self-concept, there showed statistically meaningful difference, in the level of p-value<.001. In the long run, more their self-concept was positive, more their whole health promotion behavior was high. With this, from the results of $Scheff\acute{e}$ verification, there showed meaning differences among the upper and middle group, upper and inferior group, middle and inferior group. Fifth, self-concept played the role as the most important prognostic factor with the respective to primary school students' health promotion behavior(23.0%), in the other hands, there showed positive weight of 24.0% concerning the fulfillment of whole health promotion behavior by domestic environments(1.0%). From the above results, primary school students' the fulfillment degree of health promotion behavior didn't reach to middle or inferior level. In the other hands, there showed positive effects in the correlations between self-concept and the fulfillment degree of health promotion behavior, and also high self-concept group was much positive considering inferior group in the fulfillment degree of health promotion behavior. Accordingly, more their self-concept was positive, more their fulfillment degree of health promotion behavior was effective. Eventually, in the future, there have to make an efforts to develope positive, substantial programs through their self-concept enhancement etc. in the adequate planning or operation for primary school students' health education and school health program.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.15-23
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• 1979

In the first paper of the series the five soil fertility factors were evaluated by means of principal component analysis and varimax method. They are interpreted as representing, 1) skeletal available phosporus status, 2) organnic matter status, 3) salt status 4) base status, and 5) free oxide status. In order to resynthesize such fragmented information for the overall soil fertility evaluation, the method of multiple regression analysis was adopted, using the five factor scores and yield data for Korean paddy soils as independent and dependent variables respectively. As test of linear models with different combinations of independent variables the results of t-test of regression coefficient were revealed that the organic matter status (FII) has no relevance to the yield of paddy and that the free oxides and salt supply has by it self only an insignificant contribution to the yield. The multiple correlation coefficient (R) revealed its multiple regression analysis was as low as 0.43. Introduction of quadratic terms to the linear model bettered the result. Thus multiple correlation coefficient (R) was increased as 0.59. Therefore, a coefficient of determination 0.35 was obtained by a quadratic model with interaction terms among the five fertility constituents. Generally we think that the fertility factor has more contribution to raise the rice yield in paddy and that the failure of yield prediction by fertility factor scores was caused by one of follows; 1) the roughness of the yield inspection, and 2) missextraction of fertility constituents. The second step in this study, assuming that the residuals by multiple regression analysis were due to factors other than soil fertility, we can now proceed to predicting the yield from the field characters with the classified fertility groups by means of Hayashi's theory of quantification No. 1. Such variables as fertility groups (FTYG), water availability (WATER), soil drainage (DRNG), climatic zone (CLIZ), surface soil's stickiness (STCKT), surface soil's dry consistence (DCNST), and surface soil's texture (FTEXT) are taken up as the explanatory variables. The quantification appears reasonable; the well to extremely well in soil drainage, very sticky of surface soil, inefficiency in water availability, coarse texture, and very hard to extremely hard dry consistence in soil are detrimental to the rice yield. The R was as high as 0.90 for the set of variables. But the given explanatory variables in this study were not quite effective in explaining rice yield. The method developed seems to be promising only if properly collected data are available. Conditions that should be satisfied in the yield inspection obtained from common cultivator for the purpose of deriving a prediction equation were put forward.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.660-667
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• 1998

Background: This study is to evaluate the effectiveness and application of Lecompte procedure as a treatment for various complex cardiac anomalies with pulmonary outflow tract obstruction. Methods: Between July 1988 and December 1997, 44 patients underwent Lecompte procedure in Seoul National University Children's Hospital. The male to female ratio was 24 to 20 and the mean age was 29.2 months(range, 3 to 83). Of these patients, 28(63.6%) had transposition of great arteries with ventricular septal defect and pulmonary stenosis(or pulmonary atresia), 14(31.8%) had double outlet right ventricle with pulmonary stenosis(or pulmonary atresia), and so on. The principles of the technique are 1) extension of the ventricular septal defect or conal resection, 2) construction of a intracardiac tunnel connecting the left ventricle to the aorta, and 3) direct connection, without a prosthetic conduit, of the pulmonary trunk to the right ventricle. Results: There were 3 in-hospital deaths and their causes were sustained hypoxia, myocardial failure, and sepsis, respectively. There was 1 late death due to sepsis. Reoperations were performed in 6 patients who had pulmonary outflow tract obstructions(4 cases), residual muscular ventricular septal defect(1 case), and recurrent septic vegetation(1 case). The cumulative survival rates by the Kaplan-Meier method were 92.7%, 92.7%, and 92.7% at 1, 2, and over 4 years. The reoperation free survival rates were 92.7%, 92.7%, and 70.2% at 1, 3, and over 5 years. Among the risk factors for the operative death, aortic cross clamping time had statistical significance(p<0.05) and all the risk factors for the recurrent pulmonary stenosis such as age, pulmonary artery index, and materials used for the pulmonary outflow tract reconstruction had no statistical significance(p>0.05). Conclusions: Our review suggests that Lecompte procedure is an effective treatment modality for various complex cardiac anomalies with pulmonary outflow tract obstruction. Repair in early age is possible and the rates of mortality and morbidity are also acceptable.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.517-522
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• 2002

Background: Congenital heart surgery may lead to myocardial swelling and hemodynamic instability. Delayed sternal closure may be beneficial in this setting. The purpose of this study was to assess mortality and mediastinal infection rate associated with delayed sternal closure after congenital heart surgery and to evaluate the risk factors which affect mortality and mediastinal infection rate. Material and Method: We retrospectively reviewed 40 patients who underwent delayed sternal closure after repair of congenital heart disease at Yonsei Cardiovascular Hospital, from January 1994 to May 2001. In these patients, we assessed the mortality and mediastinal infection rate, and evaluated their risk factors including operation time, bypass time, aortic cross clamp time, duration to sternal closure and postoperative artificial ventilation time. Mediastinal infection was defined to have positive culture in mediastinum. Result: Hemodynamic instability was the most common indication for delayed sternal closure(n=36) and other indications included postoperative bleeding(n=2) and conduit compression(n=2). The median age at operation was $14.4{\pm}33.4$months old(range, 2days-12years). The patients with postoperative bleeding and conduit compression were much older than the others. The sternum was left open for $4.5{\pm}3.4$ days(range, 1-20days). Overall mortality was 25%(10/40) and mediastinal infection occured in 24.3%(9/37) (3 patients were excluded in mediastinal infection for early death). In risk factor analyses, only aortic cross clamp time had statistical significance for mortality in univariate analyses. However, multivariate analyses revealed that there were no significant predictors for risk of mortality and mediastinal infection. Conclusion: Delayed sternal closure after repair of congenital cardiac disease had relatively high mortality and mediastinal infection rate. But, in patients with hemodynamic instability, postoperative bleeding and conduit compression after repair of congenital cardiac disease, delayed sternal closure may be an effective life saving method.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.127-132
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• 2010

Background: Femoropopliteal artery bypss grafting is an effective form of treatment for infrainguinal artery occlusive disease in those patients who have either intermittent claudication or resting critical ischemia. The objective of this analysis was to evaluate the long-term patency of a femoropopliteal bypass graft that is classified as an above-the-knee saphenous vein graft or an above-the-knee PTFE (polytetrafluoroethylene) graft. Material and Method:From January 1998 to February 2005, 103 above-the-knee femoro-popliteal bypasses were performed on 87 patients. There were 74 male and 13 female patients with a mean age of $65.7{\pm}9.69$ (range: 31~82). The surgical indications were intermittent claudication in 65 cases (74.7%), foot ulceration in 2 cases (2.3%), foot necrosis in 10 ases (11.5%) and toe necrosis in 10 cases (11.5%). For the bypass graft, a reversed saphenous vein was used in 31 limbs and a polytetrafluoroethylene (PTFE) prosthesis was used in 72 limbs (6 mm: 27 limbs, 8 mm: 45 limbs). The perioperative risk factors were diabetes mellitus in 33 cases (37.9%), hypertension in 47 cases (54.0%), a history of ischemic heart disease in 13 cases (14.9%) and smoking in 72 cases (82.8%). Result:There were three perioperative deaths (3.4%) and seven late deaths (8.3%). Major leg amputation was necessary in 12 patients (13.8%) during the entire course of the study. The primary patency rate at 5 years for the vein grafts, the 8 mm-PTFE grafts and the 6 mm-PTFE grafts were 84.7%, 77.4% and 74.2%, respectively and the overall primary patency rate was 78.7%, and there were no significant statistical differences among the graft groups. By using multivariate analysis, the number of patent tibial arteries was determined to be a significant factor that influenced the primary graft patency rate (p<0.005), but risk factors such as diabetes mellitus, ischemic heart disease, smoking and age had no statistically significant affect on the primary graft patency rates. Conclusion: The great saphenous vein is considered the most durable conduit for infrainguinal revascularization, but the overall results of this study show that saphenous vein and PTFE grafts have comparable patency rates when used above the knee in patients with claudication or critical ischemia. The use of PTFE above the knee is a reasonable alternative for a femoro-poplitael bypass and it is associated with acceptable long term patency rates.

• Asia pacific journal of information systems
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• v.19 no.2
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• pp.139-155
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• 2009

For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.