• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1038-1045
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• 2006

A series of experiments was conducted to test the compatibilities of two different techniques to determine elemental concentrations by INAA and ICP-MS based on both the NIST SRM 2783(air particulate on filter media) and the field samples for PM10. For NIST SRM the results of INAA were more accurate and precise for all target elements than those of ICP-MS. The comparative data set for PM10 samples collected in an industrial complex area showed that mean of concentration ratio, derived for the two different methods such as C(INNA/ICP-MS), were distinguished from each other: (1) Ba, Cu, K Mg, Na, and Sb: $0.9{\sim}1.1$; (2) Al, Co, Fe, and Mn: $0.8{\sim}1.2$; and (3) Se, Ti, and Zn: >1.3. When the results obtained from both methods were evaluated in terms of regression analysis, paired t-test, and Wilcoxon signed-rank test, the results of many elements determined from PM10 samples(such as Al, Ba, Co, Cu, Fe, K, Mn, Nd, and Sb) exhibited a fairly good agreement between the two methods, despite a wide range of variation.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.565-577
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• 2016

The objective of this study is to propose a method for computing the Natural Drought Index (NDI) that does not consider man-made drought facilities. Principal Component Analysis (PCA) was used to estimate the NDI. Three monthly moving cumulative runoff, soil moisture and precipitation were selected as input data of the NDI during 1977~2012. Observed precipitation data was collected from KMA ASOS (Korea Meteorological Association Automatic Synoptic Observation System), while model-driven runoff and soil moisture from Variable Infiltration Capacity Model (VIC Model) were used. Time series analysis, drought characteristic analysis and spatial analysis were used to assess the utilization of NDI and compare with existing SPI, SRI and SSI. The NDI precisely reflected onset and termination of past drought events with mean absolute error of 0.85 in time series analysis. It explained well duration and inter-arrival time with 1.3 and 1.0 respectively in drought characteristic analysis. Also, the NDI reflected regional drought condition well in spatial analysis. The accuracy rank of drought onset, termination, duration and inter-arrival time was calculated by using NDI, SPI, SRI and SSI. The result showed that NDI is more precise than the others. The NDI overcomes the limitation of univariate drought indices and can be useful for drought analysis as representative measure of different types of drought such as meteorological, hydrological and agricultural droughts.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.561-566
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• 2019

Objective : Functional outcomes have traditionally been evaluated and compared using subjective surveys, such as visual analog scores (VAS), the Oswestry disability index (ODI), and Short Form-36 (SF-36), to assess symptoms and quality of life. However, these surveys are limited by their subjective natures and inherent bias caused by differences in patient perceptions of symptoms. The Fitbit $Charge^{(R)}$ (Fitbit Inc., San Francisco, CA, USA) provides accurate and objective measures of physical activity. The use of this device in patients after laminectomy would provide objective physical measures that define ambulatory function, activity level, and degree of recovery. Therefore, the present study was conducted to identify relationships between the number of steps taken by patients per day and VAS pain scores, prognoses, and postoperative functional outcomes. Methods : We prospectively investigated 22 consecutive patients that underwent laminectomy for spinal stenosis or a herniated lumbar disc between June 2015 and April 2016 by the same surgeon. When patients were admitted for surgery and first visited after surgery, preoperative and postoperative functional scores were recorded using VAS scores, ODI scores, and SF-36. The VAS scores and physical activities were recorded daily from postoperative day (POD) 1 to POD 7. The relationship between daily VAS scores and daily physical activities were investigated by simple correlation analysis and the relationship between mean number of steps taken and ODI scores after surgery was subjected to simple regression analysis. In addition, Wilcoxon's signed-rank test was used to investigate the significance of pre-to-postoperative differences in VAS, ODI, and SF-36 scores. Results : Pre-to-postoperative VAS (p<0.001), ODI (p<0.001), SF-36 mental composite scores (p=0.009), and SF-36 physical composite scores (p<0.001) scores were found to be significantly different. Numbers of steps taken from POD 1 to POD 7 were negatively correlated with daily VAS scores (r=-0.981, p<0.001). In addition, the mean number of steps from POD 3 to POD 7 and the decrease in ODI conducted one month after surgery were statistically significant (p=0.029). Conclusion : Wearable devices are not only being used increasingly by consumers as lifestyle devices, but are also progressively being used in the medical area. This is the first study to demonstrate the usefulness of a wearable device for checking patient physical activity and predicting pain and prognosis after laminectomy. Based on our experience, the wearable device used to provide measures of physical activity in the present study has the potential to provide objective information on pain severity and prognosis.

• Korean Journal of Radiology
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• v.22 no.2
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• pp.159-167
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• 2021

Objective: The aim of this study was to compare the survival rates of Korean females aged 40 to 49 years with breast cancer detected by supplemental screening ultrasound (US) or screening mammography alone. Materials and Methods: This single-institution retrospective study included 240 patients with breast cancer (mean age, 45.1 ± 2.8 years) detected by US or mammography who had undergone breast surgery between 2003 and 2008. Medical records were reviewed for clinicopathologic characteristics and detection methods. Disease-free survival (DFS) and overall survival (OS) were compared between patients with breast cancer in the US and mammography groups using the log-rank test. Multivariable cox regression analysis was used to identify independent variables associated with DFS and OS. Results: Among the 240 cases of breast cancer, 43 were detected by supplemental screening US and 197 by screening mammography (mean follow-up: 7.4 years, 93.3% with dense breasts). There were 19 recurrences and 16 deaths, all occurring in the mammography group. While the US group did not differ from the mammography group in tumor stage, the patients in this group were more likely to undergo breast-conserving surgery and radiation therapy than the mammography group. The US group also showed better DFS (p = 0.016); however, OS did not differ between the two groups (p = 0.058). In the multivariable analysis, the US group showed a lower risk of recurrence (hazard ratio, 0.097; 95% confidence interval, 0.001-0.705) compared to the mammography group. Conclusion: Our study found that Korean females aged 40-49 years with US-detected breast cancer showed better DFS than those with mammography-detected breast cancer. However, there were no statistically significant differences in OS.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.73-87
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• 2016

The purpose of this study is to investigate the empirical results of Analytic Hierarchy Process/Data Envelopment Analysis-Assurance Region(AHP/DEA-AR) by using multiple regression analysis during the period of 2009-2012 with 5 inputs (number of gantry cranes, number of berth, berth length, terminal yard, and mean depth) and 2 outputs (container TEU, and number of direct calling shipping companies). Assurance Region(AR) is the most important tool to measure the efficiency of seaports, because individual seaports are characterized in terms of inputs and outputs. Traditional AHP and multiple regression analysis techniques have been used for measuring the AR. However, few previous studies exist in the field of seaport efficiency measurement. The main empirical results of this study are as follows. First, the efficiency ranking comparison between the two models (AHP/DEA-AR and multiple regression) using the Wilcoxon signed-rank test and Mann-Whitney signed-rank sum test were matched with the average level of 84.5 % and 96.3% respectively. When data for four years are used, the ratios of the significant probability are decreased to 61.4% and 92.5%. The policy implication of this study is that the policy planners of Korean port should introduce AHP/DEA-AR and multiple regression analysis when they measure the seaport efficiency and consider the port investment for enhancing the efficiency of inputs and outputs. The next study will deal with the subjects introducing the Fuzzy method, non-radial DEA, and the mixed analysis between AHP/DEA-AR and multiple regression analysis.

• The Journal of Korean Medicine
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• v.34 no.1
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• pp.80-88
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• 2013

Objectives: The purpose of this study was to examine the effect of Temporomandibular joint Balance Appliance for Golf (TBA-G) of Functional Cerebrospinal Therapy (FCST) on golf driver head speed and back muscle power. Methods: Twenty-one participants that had a golf career of 4 years or more were involved. We measured golf drive head speed and back muscular strength before and after applying TBA-G in the mouth. A paired t test or Wilcoxon singed rank test was performed to identify the difference of effect between before and after applying TBA-G, using IBM SPSS 19.0. We considered difference significant at P<0.05. Results: Driver head speed increased significantly by 2 mph (1.99%) after applying TBA-G [from $100.52{\pm}9.82$ mph ($mean{\pm}SD$) to $102.52{\pm}10.43$ mph, P<0.001]. Back muscular strength also increased by 7.28 kg (5.60%) [from $129.90{\pm}28.31$ kg to $137.18{\pm}28.81$ kg, P<0.001]. In stratification analysis, a more significant increase was found in the drive head speed and back muscular strength of groups of males with weight more than 69kg, with height more than 175cm, and with golf experience more than 7 years, compared to those of other groups. Conclusions: The results suggest that TBA-G could improve golf drive head speed and back muscular strength.

• Quality Improvement in Health Care
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• v.7 no.1
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• pp.60-70
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• 2000

Background : The aim of this study was to examine the effectiveness of the critical pathway to diabetic patients who were admitted in the hospital. Methods : For establishment of critical pathway for diabetic patients, we organized the multidisciplinary care team. During 5 months, 31 diabetic inpatients were applied the critical pathway and the results were compared with 11 diabetic inpatients who were treated with conventional way. We assessed the patients satisfaction, knowledge on the disease, compliance of medical regimen, length of stay(LOS) and hospital cost. We used the computer program SAS for statistical analysis. Data were summarized with mean, and analyzed using t-test repeated measures ANOVA and Wilcoxon rank sum test. Results : Length of stay(LOS) was remarkably shortened in critical pathway group compared with the conventional treatment group($7.6{\pm}1.23$ vs $12.0{\pm}4.73$, p<0.000). Although LOS was significantly shortened in critical pathway group, patients satisfaction was much higher than conventional treatment group. There were no significant difference of knowledge on the disease, compliance of medical regimen and blood glucose level between two groups at discharge. Hospital cost of each patients also significantly decreased in critical pathway group(890,000 won vs 1,280,000 won, p<0.05). Conclusion : These results showed that establishment of critical pathway for diabetic inpatients with team approach is the one of the way to improve the quality of diabetic patients management and to enhance the efficiency of hospital management.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.62-69
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• 2013

Visual demands associated with in-vehicle display usage and text messaging distract a driver's visual attention from the roadway. To minimize eyes-off-the-road demands, voice interaction systems are widely introduced. Under cognitively distracted condition, however, awareness of the operating environment will be degraded although the driver remains oriented to the roadway. It is also know that the risk of inattentive driving varies with age, thus systematic analysis of driving risks is required for the older drivers. This paper aims to understand the age-related driving performance degradation and visual attention changes under auditory cognitive demand which consists of three graded levels of cognitive complexity. In this study, two groups, aged 25-35 and 60-69, engaged in a delayed auditory recall task, so called N-back task, while driving a simulated highway. Comparisons of younger and older drivers' driving performance including mean speed, speed variability and standard deviation of lane position, and gaze dispersion changes, which consist of x-axis and y-axis of visual attention, were conducted. As a result, it was observed that gaze dispersion decreased with each level of demand, demonstrating that these indices can correctly rank order cognitive workload. Moreover, gaze dispersion change patterns were quite consistent in younger and older age groups. Effects were also observed on driving performance measures, but they were subtle, nonlinear, and did not effectively differentiate the levels of cognitive workload.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.303-308
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• 2008

Purpose: The purpose of this study is to develop three-dimensional computerized anthropometry(3DCA) and to compare its reliability and accuracy 3DCA with manual anthropometry(MA) for measurement of lips and nasal deformities in unilateral cleft lips and palate(UCLP) patients. Methods: Samples were consisted of six UCLP patients whose facial plaster models were available immediately before and 3 months after the cleft lip surgery. MA of the facial plaster models was carried out using an electronic caliper. In 3DCA, three-dimensional auto-measuring program was used to digitize landmarks and to measure three-dimensional virtual facial models (3DVFM), which was generated with a laser scanner and 3D virtual modeling program. Intraclass correlation coefficients(ICC) were calculated to evaluate reliability and reproducibility of the variables in both methods, and Wilcoxon's signed rank test was done to investigate the difference in values of the same variables of facial models of each patient between two methods. Results: All ICC values were higher than 0.8, so both methods could be considered reliable. Although most variables showed statistical differences between two methods(p<0.05), differences between mean values were very small and could be considered not significant in clinical situation. Conclusion: In clinical situation, 3DCA can be an objective, reliable and accurate tool for evaluation of lips and nasal deformities in the cleft patients.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.243-247
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• 2008

Purpose: For a proper wound care, the correct evaluation of wound is very important. Usually the evaluation of wound was subjective, and as a result, wound care was empirical. There were many attempts to objectify the wound evaluation, and one of them was measurement of the wound pH. The purpose of this study is to observe the wound pH changes during wound healing phase. Methods: From 2005 to 2007, we measured the pH values of 6 acute wounds, which were split thickness skin graft donor sites. In addition, we measured the pH values of 18 chronic wounds, which were 17 pressure sores and 1 tuberculosis ulcer. After pH meter ($SkinCheck1^{(R)}$, Hanna Instruments, Italy) was calibrated, wound pH was checked. Wound was cleansed with saline gauze and dressed with polyurethane foam dressing($Medifoam^{(R)}$, Biopol, Korea). Results: In split thickness skin graft donor sites, the pH raised(mean pH value: $7.45{\rightarrow}7.62$) when the wound was on the process of healing(*p=0.027, analysis of Wilcoxon signed-rank test). If wound became re-epithelialised, the pH value dropped to that of normal skin. However, we could not find a relation between time and the pH values in chronic wound. Conclusion: We could observe the consistent wound pH changes during wound healing phase in acute wound.