• Journal of the Korean Society of Radiology
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• v.9 no.6
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• pp.357-362
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• 2015

This study was to evaluate the usefulness through the comparison of patients group and healthy control group by acquiring a variety of functional parameters index from time-activity curves of salivary gland scan using 99mTc-pertechnetate. From December 2014 to February 2015, had the targets of 30 patients with dry mouth and 10 people in healthy control group underwent the salivary gland scan. After intravenous injection of 370 MBq of 99mTc-pertechnetate, Vitamin C powder stimulation was administerd orally at 20 min and then 10 minutes were taken scan. The method of quantitative analysis was as follows, the time-activity curve was drawn after the parotid gland and submandible gland were prescribed as a region of interest, a variety of function parameters index was obtained in each position of the curve, and the patients group and the control group were compared. As for the methods applied in comparison and measurement, uptake ratio (UR), time at maximum counts (Tmax), time at minimum counts (Tmin), maximum accumulation (MA), accumulation velocity, maximum secretion (MS), maximum stimulation secretion (MSS), and secretion velocity (SV) were used. In the comparison of functional parameters index of patient group and normal group, the healthy normal group showed significant difference compared to the patient group in all indices except for the minimum radioactivity time (Tmin), and also in terms of variation over time the normal group showed significant difference compared to the patient group (p<0.05). Consequently, it was considered that the quantitative analysis that used a variety of function parameters index would be useful for evaluating the function of the salivary glands of the patients with dry mouth as an objective and standardized information.

• Smart Media Journal
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• v.10 no.3
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• pp.39-47
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• 2021

Enhanced index tracking is a problem of optimizing the objective function to generate returns above the index based on the index tracking that follows the market return. In order to avoid problems such as large transaction costs and illiquidity, we used a method of constructing a portfolio by selecting only some of the stocks included in the index. Commonly used enhanced index tracking methods tried to find the optimal portfolio with only one objective function in all tested periods, but it is almost impossible to find the ultimate strategy that always works well in the volatile financial market. In addition, it is important to improve generalization performance beyond optimizing the objective function for training data due to the nature of the financial market, where statistical characteristics change significantly over time, but existing methods have a limitation in that there is no direct discussion for this. In order to solve these problems, this paper proposes ensemble learning that composes a portfolio by combining several objective functions and a 3-stage portfolio selection algorithm that can select a portfolio by applying criteria other than the objective function to the training data. The proposed method in an experiment using the S&P500 index shows Sharpe ratio that is 27% higher than the index and the existing methods, showing that the 3-stage portfolio selection algorithm and ensemble learning are effective in selecting an enhanced index portfolio.

• Journal of Distribution Science
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• v.16 no.12
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• pp.5-11
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• 2018

Purpose - We investigate the relationship between economic policy uncertainty (EPU) of the US and China and housing distribution economy in Korea using EPU indexes of two countries and the economic indicators in Korea. Research design, data, and methodology - We use the data such as the Korean housing price stability index (HPSI), housing purchase price index (HPPI), housing lease price index (HLPI), banking stock index (BSI), and consumer price index (CPI) with EPU indexes from January 1999 to December 2017. As an empirical methodology, we select the vector error correction model (VECM) due to the existence of cointegration. Result - As results of the impulse response function, the impact of the US EPU index has initially a negative response on the Korean HPSI, HPPI, and HLPI referring the housing distribution market including the economic variables, BSI, and CPI. Likewise, the impact of index in China has initially a negative response on economic indicators except the BSI in Korea. Conclusions - This study shows that the EPU index of the US has significantly negative relationships on all economic indicators in Korea. In this study, we reveal EPU of the US and China has dynamic impact on housing distribution economy returns in Korea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.18
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• pp.71-80
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• 1988

Process capability implies the qualitative capability of a process, and it is necessary to specify the process capability by quantification and to evaluate the level with the specified standardizaion. But the process capability index is currently used to evaluate the performance of quality control activity. without considering the characteristics of process structure or the economy of management. Here the researcher would like to redefine process capability and emphasize its index may be used as the measure of managerial assessment and the objective of process quality control in full consideration of the economic aspects of process characteristics. Too little or too much process capability causes a loss of or excess. The proper economic level of process capability varies to each process. The procedure of taking the optimum process capability index is derived from the expected profit function, whereas each method is studied in cases of normal process with one-sided specification and two-sided specification. In addition, the process capability index is presented as a method of quality assurance. And an example is exhibited on wrapping process of 'A' company. The results of this study are summarized at follows. First, though the norminalization of the process capability index is possible by the existing methods, the optimum process capability index can vary to the situation of each process. So, the optimum process capability index which is suggested in this dissertation should be used as the standard to assess process capability. Second, the process capability index can take its effect not just in indicating quality control or managerial records but also in the management of high qualify assurance.

• Journal of dental hygiene science
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• v.22 no.2
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• pp.67-74
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• 2022

Background: Depression and cognitive function have a positive effect on the improvement of quality of life and extension of lifespan in the elderly. In addition, it appears as a major factor influencing oral health status. Therefore, this study looked at the relationship between the Geriatric Oral Health Assessment Index (GOHAI), depression, and cognitive function in the elderly using the Korea Longitudinal Study of Aging. Methods: In this study, 4,535 elderly people aged 65 years and over were targeted using the 7th data of the 2018 Korea Longitudinal Study of Aging. A t-test and ANOVA analysis were performed to compare GOHAI, depression, and cognitive function by group. In addition, hierarchical multiple linear regression was performed to understand the effect of the elderly's perceived depression scale and cognitive ability on GOHAI. Results: As a result of adding the depression scale and cognitive function variables to Model 2, the explanatory power was 22%. Educational level, marital status, private health insurance subscription, average monthly allowance, subjective health status, use of dentures, smoking status, economic activity, depression scale, and cognitive function were found to have significant influence (p<0.05). In addition, when controlled and viewed with all factors, depression and cognitive function were found to have an effect on oral health-related quality of life. Conclusion: The findings indicate that depression and cognitive function are associated with oral health-related quality of life in the Korean elderly. As the age increases, the quality of life declines due to depression and cognitive function problems, in addition to oral discomfort, eating disorders, and physical discomfort.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.427-431
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• 2006

Pulse Doppler ultrasonographic evaluation was performed to investigate the resistive index (RI) of the Interlobar renal artery in 17 dogs (32 kidneys) which were diagnosed with an acute renal failure caused by ochratoxin-A and citrinin contaminated commercial diet. RI was investigated in 7 normal beagle dogs and recovered patients. The mean of RI was resulted as $0.69{\pm}0.04$ in normal dog, however, significantly (p<0.001) increased as $0.76{\pm}0.05$ in renal failure dog. But RI had no relationship with the results of blood chemistry, urine analysis, and excretory urographic image quality. From these results, even though the results of the renal function test were within a normal reference range, it was considered that RI index is more reliable to represent a damaged renal parenchyma, and may have the potential to be a useful clinical tool in monitoring of the renal function.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.111-115
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• 2009

Purpose: The aim of this study was to present fundamental information regarding clinical prognosis and clinical criteria for therapeutic intervention in stroke patients with focal pons infarction. Methods: Four stroke patients (male: 2, female: 2) who were diagnosed with pons infarction were recruited. All subjects had motor functions evaluated using methods such as the Motricity Index (MI), the Modified Brunnstrom Classification (MBC), Functional Ambulatory Category (FAC), and the Bathel Index (BI). Evaluations were done at least 4 times over a period that was approximately 8~11 months from stroke onset. We compared the final evaluation with the first evaluation. Results: All patients with focal pons infarction showed improvement with time in motor function. The physical strength of all patients was improved to normal or good grades from zero or trace grades in the Motricity Index test. Also, other motor functions such as ambulatory capacity and activities of daily living (ADL) improved with time. Conclusion: Aspects of functional recovery and clinical prognosis are clearly predictable for specific patients with focal pons infarction. In addition, adequate therapeutic interventions can be provided clinical criterion to patients, according to aspect of functional recovery. Accordingly, patients with pons infarction change for the better over time.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.242-249
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• 2004

This study was conducted to develop a forest fire occurrence model using meteorological characteristics for the practical purpose of forecasting forest fire danger. Forest fire in South Korea is highly influenced by humidity, wind speed, and temperature. To effectively forecast forest fire occurrence, we need to develop a forest fire danger rating model using weather factors associated with forest fire. Forest fore occurrence patterns were investigated statistically to develop a forest fire danger rating index using time series weather data sets collected from 8 meteorological observation centers. The data sets were for 5 years from 1997 through 2001. Development of the forest fire occurrence probability model used a logistic regression function with forest fire occurrence data and meteorological variables. An eight-province probability model by was developed. The meteorological variables that emerged as affective to forest fire occurrence are effective humidity, wind speed, and temperature. A forest fire occurrence danger rating index of through 10 was developed as a function of daily weather index (DWI).

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.31-37
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• 2023

PURPOSE: This study aimed to investigate the relationship between being underweight and respiratory function indicators such as pulmonary function, respiratory muscle strength, and diaphragm thickness in normal adults without lung disease. METHODS: The participants in this experiment were thirty young adults. To compare the respiratory function between the underweight and normal weight individuals, 15 participants were selected from each of the underweight and normal weight groups based on body mass index. Respiratory function tests were conducted through pulmonary function tests and respiratory muscle strength tests. Diaphragm thickness was measure with ultrasonography, and physical characteristics were obtained from grip strength and waist circumference. An independent t-test was used to compare the averages of the parameters measured in the two groups. RESULTS: In the respiratory function tests between the two groups, statistically significant differences (p < .05) emerged in the ratio of the predicted forced vital capacity (%FVC), the ratio of the predicted forced expiratory volume in one second (%FEV1), maximal expiratory pressure (MEP), and diaphragm thickness at the functional residual capacity (FRC). There was no statistically significant difference in the forced vital capacity, forced expiratory volume in one second, maximal inspiratory pressure, diaphragm thickness at the total lung capacity, and thickening ratio (p > .05). CONCLUSION: Decreases in some variables of respiratory function, such as the %FVC, %FEV1, MEP, and diaphragm thickness at the FRC were observed in underweight subjects. However, it is difficult to determine whether it affected the overall respiratory function. Future studies are needed to clearly identify the relationship between being underweight and respiratory function.

• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.33-47
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• 2004

Even though the price of extracted but unprocessed coal has been available in Korea, the use of it as scarcity index would be inappropriate because of price subsidy. Following Halvorsen and Smith(1984), Kim and Lee(2002) derived estimates of the shadow price of unextracted coal by estimating the restricted cost function and differentiating with respect to the quantity of coal extracted. In Korea, however, due to the limited data the capital prices have been computed inconsistently case by case without relying on the robust formula like the Christensen-Jorgenson methodology used in US, which could result in biased estimators of the restricted cost function. In the paper the shadow prices of the resources in situ are obtained by measuring an input distance function defined by Shephard (1970), which requires only the data on the quantities of inputs and output. Empirical results for the Korean coal mining industry show that these shadow prices as a coal scarcity have increased fast by approximately three times in comparisons with those obtained by Kim and Lee.