• The Korean Journal of Nuclear Medicine
• /
• v.28 no.3
• /
• pp.317-325
• /
• 1994

The accuracy of dipyridamole stress/rest $^{99m}Tc$-MIBI myocardial imaging for detection of ischemia depends on reproducible image interpretation. To evaluate the reproducibility of visual assessment, agreement in interpretation among two independent observers, blind-ed to clinical data, was evaluated in SPECT images of 131 patients (94 males, 38 females; mean age $58{\pm}7yr$) with suspected coronary artery disease who underwent both dipyridamole stress/rest $^{99m}Tc$-MIBI myocardial SPECT and coronary angiography. The left ventricle was divided into twenty-nine segments in stress and rest SPECT images and each segment was visually graded according to a five-point scale (segmental score : 0=normal, 1=equivocal, 2=mild decrease, 3=severe decrease and 4=absent uptake). Overall concordance of segmental scoring between the two observers was 80%. The Pear-son's correlation coefficient (r) of the segmental scores for stress and rest images were 0.67 and 0.65, respectively, while the difference in score between the two images showed a correlation of 0.45 (all p<0.001). Agreement between two observers in final SPECT diagnosis as absence or presence of disease was 93%. The degree of agreement in segmental scoring showed no difference between patients with or without agreement as to the presence of disease. Therefore it appeared that cases with inconcordant diagnosis between the 2 observers were mainly due to a difference in individual threshold for interpretating the significance of a particular decreased uptake area rather than to a difference in perceiving the degree of the hypoactivity Thus, establishment of individual optimum thresholds in visual interpretation of myocardial SPECT may be helpful to improve reproducibility and accuracy of scan diagnosis.

• Communications of Mathematical Education
• /
• v.26 no.3
• /
• pp.251-271
• /
• 2012

The purpose of this study is: 1) to determine error sources and the effects of each error source, 2) to investigate optimal measuring conditions from holistic and analytic scoring methods, and 3) to compare the value of reliability between Cronbach's alpha and the generalizability coefficient in self-introduction letter and teacher's recommendation letter based on the generalizability theory in identification of mathematical gifted students by observations and nominations. Data of this study were collected from the science education institute for the gifted attached to the university located within in a capital city for the 2011 academic year. Scores form two raters using holistic and analytic scoring methods in both assessment types were used. The results of this study were as follows. First, as to both assessment types, error sources for people were relatively large regardless of scoring methods. However, error sources for raters in holistic scoring methods had a more significant impact than those of analytic scoring methods. Second, to set optimal measuring conditions in the self-introduction letter and teacher's recommendation letter, if we fixed the number of raters into 2 based on holistic scoring methods, at least 5 and 10 content domains were needed, respectively. In addition, the number of items in teacher's recommendation letter should be more than 3 when we fixed the number of content domains into 4, and the number of items in self-introduction letter should be more than 8 when we fixed the number of content domains into 6 using analytic scoring methods. Third, Cronbach's alpha having only a single source of errors was higher than the generalizability coefficient regardless of assessment types and scoring methods. Hence we recommend that generalizability coefficient based on various error sources such as raters, content domains, and items should be considered to keep a satisfactory level of reliability in both assessment types.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.1
• /
• pp.11-18
• /
• 2007

Background: Patients with chronic obstructive pulmonary disease (COPD) have often been reported to suffer from depression and anxiety possibly due to the exacerbation, hospitalization and mortality of COPD. However,scarce data are available in Korea. This study assessed degree of depression and anxiety, and evaluated the factors associated with depressive symptoms in COPD. Methods: The cross-sectional data on the lung function measurements, smoking behavior, body mass index (BMI), age, gender, depressive symptoms using Beck Depression Inventory (BDI) and anxiety using the State-Trait Anxiety Inventory (STAI) were evaluated in 72 outpatients with COPD and 50 controls without underling lung diseases from September, 2005 to October, 2006 in the Ewha medical center. Results: 1) The age, body mass index (BMI) and serum albumin levels were similar in the patients and controls. The BDI scores (16(0-37) vs. 12(1-30), p=0.001) and the prevalence of depression (36% vs. 6%, p<0.0001) were higher in the COPD patients than in the controls. In the COPD group, the prevalence of depression increased with increasing GOLD stage (p=0.008). The prevalence was 18%(4/22), in mild cases, 30%(6/20) in moderate cases, 52%(13/25) in severe cases and 60%(3/5) in very severe cases. 2) The SAI and TAI scores were higher in the COPD patients (44(20-67) and 47(20-66)) than in the healthy controls (39(26-65) and 44(33-90)). There were a significant correlation between the depression and anxiety scores (p<0.001). 3) A lower BMI, lower postbronchodilator $FEV_1$, current smoking behavior and severity of COPD were univariately associated with the depressive group in COPD, 4) while multivariate logistic analysis revealed only the severe-to-very severe group (OR 3.9, 95% CI 1.2 to 12.9) to be independently associated with depressive symptoms. Conclusion: COPD is strongly associated with depression and anxiety. Therfore, screening for psychological problems in COPD patients is essential, particularly in patients with severe-to-very severe COPD.

• Journal of dental hygiene science
• /
• v.13 no.3
• /
• pp.254-263
• /
• 2013

This study is to develop an evaluation index for infection control and to verify its validity by examining each set of weighted data collected from 121 infection control personnel at dental hospitals who agreed to the preliminary survey and advisory. The study was conducted from 14th December, 2010 to 31st January, 2011, and PASW Statistics 18.0 and AMOS 5.0 had been used for the statistical data analysis. As a result of the study, five evaluation factors with 21 sub-indicators have been identified at structural level, eight evaluation factors with 32 sub-indicators at processing level, and one evaluation fact with five sub-indicators at resulting level, total 14 evaluation factors with 58 sub-indicators throughout all levels. The path analysis added on the result that 'standard precautions ($x_1$)', 'infection control support system ($x_2$)', 'internal and external characteristics ($x_3$)' are exogenous variables that affect on other variables, and 'standard infection control ($y_1$)','Organization equipment management handwashing ($y_2$)', 'environmental infection control ($y_3$), 'personal protective equipment ($y_4$)', 'waste and laundry management ($y_5$)' are endogenous variables that are infulenced by others. The standardized metrics are more needed than anything else when examining on infection control. This study attempts to develop proper dental infection control metrics adequately adjusted for domestic circumstances, and therefore to contribute to effective systematic management and decision-making in infection control.

• Korean Journal of Poultry Science
• /
• v.43 no.4
• /
• pp.229-233
• /
• 2016

This study was conducted to compare three commercially available egg testing devices for measuring egg quality. The devices used were a Laser-type (automatic), a Ultrasonic-type (automatic), and a Probe-type (manual). Fresh eggs weighing 60~68 grams were obtained from a commercial hen farm. Three trials were conducted. In Trial 1, a total of 50 eggs were successively analyzed by the three egg testing devices. In Trial 2, fresh eggs were successively analyzed by a combination of two egg testing devices. In Trial 3, a total of 600 eggs (weighing 60~68 grams) laid by same flock were selected, further divided into three sub-groups with a total of 200 eggs, and analyzed by an egg testing device. In Trials 1 and 2, no apparent difference was observed in egg weight between egg testing devices. However, albumin height was scored highest in the Ultrasonic-type egg tester followed by the Probe-type and Laser-type (Trials 1 and 2). Consequently, the Haugh unit was similarly altered. Yolk color was highest in the Laser-type egg tester followed by the Ultrasonic-type and Probe-type (Trials 1 and 2). When fresh eggs laid by a single flock were independently analyzed by three devices, egg weight did not differ, but albumin height and Haugh unit were higher (p<0.05) in the Ultrasonic-type egg tester than in the Probe-type or Laser-type testers. However, Laser-type testers produced higher (p<0.05) yolk color values than the Ultrasonic-type or Probe-type egg testers. In conclusion, the commercially available egg testing devices exhibited performance differences in measuring egg qualities, which warrants further consideration as to whether the magnitude of bias and precision between the devices could be acceptable in the egg grading system, especially when assessing eggs stored for certain durations.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.1-17
• /
• 2013

This research was to examine the effects of downsizing kitchen employees in a hotel on their job efficiency and to verify differences in the individuals' behavior characteristics according to DISC behavior types in this causal relationship. Through SPSS 17.0 program, factor analysis, reliability analysis, correlation analysis, and multiple regression analysis were conducted on 200 samples secured for an empirical research. Two factors for the downsizing items and two factors for the items related to job attitude were extracted. Hypothesis 1 was that the downsizing within a hotel has significant negative (-) effects on job attitude. As a result of the verification, it was found that downsizing had significantly negative effects on the job attitude of cooking employees as factors for organizational commitment in employment circumstances (${\beta}$=-.256), and employment anxiety (${\beta}$=-.258), and as factors for job satisfaction in employment circumstances (${\beta}$=-.319), and employment anxiety (${\beta}$=-.174). Hypothesis 2 was that the downsizing according to DISC behavior types has significant negative (-) effects on job attitude. As a result of the verification, it was found that in the organizational commitment factors, the dominance type (D) was more influenced by employment anxiety (${\beta}$=-.435) than by any other types, and the conscientiousness type (C) was not influenced by organizational commitment. In the job satisfaction factors, the steadiness type (S) was more influenced by the changes in employment circumstances (${\beta}$=-.414) than by other types, and the dominance type (D) was not influenced. Based on the results of this research, it can be said that hotel's downsizing strategies influence job attitude such as organizational commitment and job satisfaction of cooking employees, and that there are differences in the influences according to the individuals' behavior types of kitchen employees.

• Journal of Korean Society of Forest Science
• /
• v.104 no.1
• /
• pp.150-161
• /
• 2015

The purpose of this study was to obtain the basic data for the effective development and operation of forest healing by analysing the preference of adults on the forest therapy program. The survey of 516 normal adults on the forest therapy program was conducted. Using SPSS 21.0 Program, data analysis of descriptive statistics and correlation analysis of each program confirmed number of covariate, and so we conducted a factor analysis to short meaningful data. And then we looked at the forest healing program preference difference according to demographic characteristics(sex, age, residence, occupation) through reliability analysis, frequency analysis, T-test, analysis of variance(ANOVA). Facter analysis was performed by use of the VariMax orthogonal rotation factor analysis to abbreviate 37 forest therapy program. Through this, the program has been reduced such as 7 program group(1: psychology-based treatment, 2: teaching and counselling-based treatment, 3: camping and forest bath-based treatment, 4: diet-based treatment, 5: nature and plant-based treatment, 6: meditation-based treatment, 7: respiration and yoga-based treatment) and 7 independent programs(1: sleeping in the forest, 2: vision quest, 3: soaking in water, 4: walking wearing shoes, 5: viewing the forest, 6: mountaineering, 7: athletics in the forest). With this criterion, the forest therapy program difference in accordance with sex, age, residence, occupation has been investigated. First, it was verified that there was a significant difference between male and female in the group of such as psychology-based treatment, diet-based treatment, mountaineering. Second, there appeared a significant difference in groups such as teaching and counselling-based treatment, camping and forest bath-based treatment, nature and plant-based treatment, respiration and yoga-based treatment, athletics in the forest. Third, according to the residence, there appeared a significant difference in groups such as psychology-based treatment, teaching and counselling-based treatment, diet-based treatment, nature and plant-based treatment, meditation-based treatment, vision quest, mountaineering, athletics in the forest. Fourth, according to the occupation, there appeared a significant difference in groups such as nature and plant-based treatment, medication-based treatment, vision quest, walking wearing shoes, viewing the forest, mountaineering. As shown before, it seems to be necessary that we should be mindful of this investigation which shows variety of preference of adults on the forest therapy program according to demographic characteristics. We expect the results of this study to be utilized as basic data for the development of forest therapy program targeting on adults.

• Tuberculosis and Respiratory Diseases
• /
• v.54 no.5
• /
• pp.485-494
• /
• 2003

Background : Most previous studies regarding the role of GSTMl and GSTT1 on lung cancer risk have been focused mainly on male smokers. However, epidemiological characteristics, histologic types and risk factors are different in female and male lung cancers, we investigated the association between these genotypes and lung cancer risk in males and females separately. Materials and Methods : The study population consisted of 253 lung cancer (153 males and 100 females) and 243 controls (140 males and 103 females). GSTM1 and GSTT1 genotypes were determined by a multiplex PCR. Results : In the male population, neither GSTM1 nor GSTT1 null genotype showed significant difference between cases and controls. In the female population, the frequencies of GSTM1 null genotype showed no significant difference between cases and controls. However, the frequencies of GSTT1 null genotype was significantly higher in cases (70.3%) than controls (55.3%, odds ratio (OR)=2.18; 95% confidence interval (CI=l.21-3.93). When the female population was stratified by age and smoking status, the ORs for GSTT1 null genotype were significantly higher in subgroups of ${\leq}60$ years (OR=4.82; 95% CI=l.61-14.4) and never-smokers (OR=4.29; 95% CI=1.94-9.48) but not in subgroups of >60 years or smokers. When stratifying the female never-smokers by age, the ORs for GSTT1 null genotype were significantly higher in both age groups of ${\leq}60$ years (OR=7.64; 95% CI=2.00-29.2) and >60 years (OR=2.89; 95% CI=1.05-7.94). Conclusion : We found that GSTT1 null genotype was associated with an increased risk of lung cancer in Korean female never-smokers. This result suggests that GSTT1 null genotype could be used as a biomarker for genetic susceptibility to lung cancer in Korean female never-smokers.

• KIPS Transactions on Computer and Communication Systems
• /
• v.1 no.3
• /
• pp.143-150
• /
• 2012

A simulation methodology and corresponding program based on it is to be discussed for analyzing the effects of the networking operation of existing DHC system in connection with CHP system on-site. The practical simulation for arbitrary areas with various building compositions is carried out for the analysis of operational features in both systems, and the various aspects of thermal energy grids with connecting operation are highlighted through the detailed assessment of predicted results. The intrinsic operational features of CHP prime movers, gas engine, gas turbine etc., are effectively implemented by realizing the performance data, i.e. actual operation efficiency in the full and part loads range. For the sake of simplicity, a simple mathematical correlation model is proposed for simulating various aspects of change effectively on the existing DHC system side due to the connecting operation, instead of performing cycle simulations separately. The empirical correlations are developed using the hourly based annual operation data for a branch of the Korean District Heating Corporation (KDHC) and are implicit in relation between main operation parameters such as fuel consumption by use, heat and power production. In the simulation, a variety of system configurations are able to be considered according to any combination of the probable CHP prime-movers, absorption or turbo type cooling chillers of every kind and capacity. From the analysis of the thermal network operation simulations, it is found that the newly proposed methodology of mathematical correlation for modelling of the existing DHC system functions effectively in reflecting the operational variations due to thermal energy grids with connecting operation. The effects of intrinsic features of CHP prime-movers, e.g. the different ratio of heat and power production, various combinations of different types of chillers (i.e. absorption and turbo types) on the overall system operation are discussed in detail with the consideration of operation schemes and corresponding simulation algorithms.

• Journal of Intelligence and Information Systems
• /
• v.21 no.1
• /
• pp.161-177
• /
• 2015

With the rapid evolution of technology, the size, number, and the type of databases has increased concomitantly, so data mining approaches face many challenging applications from databases. One such application is discovery of fraud patterns from agricultural product wholesale transaction instances. The agricultural product wholesale market in Korea is huge, and vast numbers of transactions have been made every day. The demand for agricultural products continues to grow, and the use of electronic auction systems raises the efficiency of operations of wholesale market. Certainly, the number of unusual transactions is also assumed to be increased in proportion to the trading amount, where an unusual transaction is often the first sign of fraud. However, it is very difficult to identify and detect these transactions and the corresponding fraud occurred in agricultural product wholesale market because the types of fraud are more intelligent than ever before. The fraud can be detected by verifying the overall transaction records manually, but it requires significant amount of human resources, and ultimately is not a practical approach. Frauds also can be revealed by victim's report or complaint. But there are usually no victims in the agricultural product wholesale frauds because they are committed by collusion of an auction company and an intermediary wholesaler. Nevertheless, it is required to monitor transaction records continuously and to make an effort to prevent any fraud, because the fraud not only disturbs the fair trade order of the market but also reduces the credibility of the market rapidly. Applying data mining to such an environment is very useful since it can discover unknown fraud patterns or features from a large volume of transaction data properly. The objective of this research is to empirically investigate the factors necessary to detect fraud transactions in an agricultural product wholesale market by developing a data mining based fraud detection model. One of major frauds is the phantom transaction, which is a colluding transaction by the seller(auction company or forwarder) and buyer(intermediary wholesaler) to commit the fraud transaction. They pretend to fulfill the transaction by recording false data in the online transaction processing system without actually selling products, and the seller receives money from the buyer. This leads to the overstatement of sales performance and illegal money transfers, which reduces the credibility of market. This paper reviews the environment of wholesale market such as types of transactions, roles of participants of the market, and various types and characteristics of frauds, and introduces the whole process of developing the phantom transaction detection model. The process consists of the following 4 modules: (1) Data cleaning and standardization (2) Statistical data analysis such as distribution and correlation analysis, (3) Construction of classification model using decision-tree induction approach, (4) Verification of the model in terms of hit ratio. We collected real data from 6 associations of agricultural producers in metropolitan markets. Final model with a decision-tree induction approach revealed that monthly average trading price of item offered by forwarders is a key variable in detecting the phantom transaction. The verification procedure also confirmed the suitability of the results. However, even though the performance of the results of this research is satisfactory, sensitive issues are still remained for improving classification accuracy and conciseness of rules. One such issue is the robustness of data mining model. Data mining is very much data-oriented, so data mining models tend to be very sensitive to changes of data or situations. Thus, it is evident that this non-robustness of data mining model requires continuous remodeling as data or situation changes. We hope that this paper suggest valuable guideline to organizations and companies that consider introducing or constructing a fraud detection model in the future.