• Journal of Gastric Cancer
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• v.11 no.3
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• pp.173-179
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• 2011

Purpose: It is difficult to obtain biopsies from gastrointestinal stromal tumors (GISTs) prior to surgery because GISTs are submucoal tumors, despite being the most common nonepithelial neoplasms of the gastrointestinal tract. Unlike anatomic imaging techniques, PET-CT, which is a molecular imaging tool, can be a useful technique for assessing tumor activity and predicting the malignant potential of certain tumors. Thus, we aimed to evaluate the usefulness of PET-CT as a pre-operative prognostic factor for GISTs by analyzing the correlation between the existing post-operative prognostic factors and the maximum SUV uptake (SUVmax) of pre-operative 18F-fluoro-2-deoxyglucose (FDG) PET-CT. Materials and Methods: The study was conducted on 26 patients who were diagnosed with gastric GISTs and underwent surgery after being examined with pre-operative FDG PET-CT. An analysis of the correlation bewteen (i) NIH risk classification and the Ki-67 proliferation index, which are post-operative prognostic factors, and (ii) the SUVmax of PET-CT, which is a pre-operative prognostic factor, was performed. Results: There were significant correlations between (i) SUVmax and (ii) Ki-67 index, tumor size, mitotic count, and NIH risk group (r=0.854, 0.888, 0.791, and 0.756, respectively). The optimal cut-off value for SUVmax was 3.94 between "low-risk malignancy" and "high-risk malignancy" groups. The sensitivity and specificity of SUVmax for predicting the risk of malignancy were 85.7% and 94.7%, respectively. Conclusions: The SUVmax of PET-CT is associated with Ki-67 index, tumor size, mitotic count, and NIH classification. Therefore, it is believed that PET-CT is a relatively safe, non-invasive diagnostic tool for assessing malignant potential pre-operatively.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.1
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• pp.83-92
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• 2014

Objectives To evaluate the clinical usefulness between muscle energy techniques (MET) and transcutaneous electrical nerve stimulator (TENS), we performed both on elector spinae muscle of acute low back pain patients. Methods After performing MET and TENS, we compared both in terms of electrical activity. We performed MET or TENS on elector spinae muscle of acute low back pain patients in each group (n=15,15). After performing MET or TENS, we analyzed root mean square (RMS), median edge frequency (MEF) and asymmetry index (AI). Results 1. After performing MET on elector spinae muscle of acute low back pain patients, RMS was significantly decreased compared with before (p<0.005). 2. After performing TENS on elector spinae muscle of acute low back pain patients, RMS was significantly decreased compared with before (p<0.005). 3. After performing MET on elector spinae muscle of acute low back pain patients, asymmetric index was significantly decreased compared with before (p<0.05). Conclusions According to above results, performing MET on elector spinae muscle of acute low back pain patients has effect in terms of RMS and asymmetric index. And performing TENS on elector spinae muscle of acute low back pain patients also has similar effect in terms of RMS but has not in terms of asymmetric index.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.639-653
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• 2020

Baker et al. (Quarterly Journal of Economics, 134, 1593-1636, 2016) developed an Economic Policy Uncertainty (EPU) index for South Korea in the same way as the U.S. EPU Index. However, the South Korean EPU index of Baker et al. (2016) has limitations as it did not fully reflect South Korean situation in terms of keyword selection and the selection of newspapers. We develop monthly South Korean economic policy uncertainty indexes with different keywords and news media. Various analyses have been conducted in order to examine the usefulness of the newly compiled indexes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.3
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• pp.169-172
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• 2003

Purpose : We examined the relationship between BIS, sedation score and plasma midazolam concentration to verify the usefulness of BIS to assess the patient's consciousness during sedation. Patients and Methods : Twenty-five young, healthy adult volunteers participated in this clinical study. Midazolam was administered intravenously up to 0.08 mg/kg to induce unconsciousness and we monitored the patient's physiological and conscious status until complete recovery from sedation. BIS and sedation score were measured before sedation, 10, 20, 30 minutes after midazolam administration. Plasma midazolam concentration was measured 10 minutes after midazolam administration. BIS was measured using A-2000 BISTM monitor (Aspect Medical Systems, USA) and the degree of sedation was evaluated with the sedation score. Results : The BIS score correlated with the sedation score (r = 0.676; P < 0.05). With the decreased plasma midazolam concentration, the correlation was better with sedation score (r = -0.656). Although BIS values did not correlate with calculated plasma concentration of midazolam (r = 0.467) at 10 minutes after midazolam administration, values after sedation were well distinguished from those before sedation. Conclusions : BIS is known for an effective predictor of patient's hypnotic state, and it is correlated with the sedation score. But, it doesn't always coincide with the clinical parameters of depth of sedation. So more attention is needed using BIS only during sedation, and it is advisable that the patient's consciousness is monitored with variable sedation score systems every several minutes.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.539-546
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• 2019

Liver biopsy is invasive and it is a risk of complications. Nevertheless, liver biopsy is gold standard for predicting liver fibrosis. To compensate for these shortcomings, in this study, the liver fibrosis stage was divided using Fibroscan(R) in 200 chronic hepatitis C patients. And, the usefulness and cut-off values of fibrosis index based on four factors(FIB-4), AST to platelet ratio index(APRI) and AST/ALT ratio(AAR) calculated as serum tests were investigated by analyzing ROC curve. As a result, using FIB-4 and APRI rather than AAR is appropriate for evaluation of liver fibrosis. And using APRI to predict significant Fibrosis(F2) and FIB-4 is considered useful for predicting cirrhosis(F4). By applying the advantages of the serum based liver fibrosis marker, which are convenient and repeatable, liver fibrosis follow-up term can be reduced, and furthermore, the prevalence of liver cirrhosis and hepatocellular carcinoma(HCC) can be reduced.

• Clinical and Experimental Pediatrics
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• v.50 no.7
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• pp.629-635
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• 2007

Purpose : This study was conducted to assess the usefulness of fat-free mass index (FFMI) and fat mass index (FMI) as novel expression methods of body composition in children. Methods : A total of 466 Second grade students-248 boys and 218 girls- from all elementary schools the Gwacheon City underwent anthropometric measures including bioelectrical impedance analysis (BIA) and biochemical tests. The correlation coefficients between obesity indices, including FMI and FFMI, and metabolic risk factors, were assessed. Metabolic risk factors of children with increased FMI were compared with those of children with normal FMI. We compared FMI and FFMI percentile distribution between this study's subjects and the subjects of the Fukuoka body composition study. Results : FMI was lower and FFMI was higher in this study's subjects compared to the subjects of the Fukuoka body composition study. FMI was correlated with other obesity indices and several metabolic risk factors. Metabolic risk was higher in children with increased FMI than in children with normal FMI. Conclusion : FMI and FFMI were useful indicators in comparing difference of body composition among children that had different body size and growth. High FMI was related to increase of metabolic risk in children.

• Journal of Sasang Constitutional Medicine
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• v.33 no.2
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• pp.1-13
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• 2021

Introduction The previous study showed that the psychological Sasang Personality Questionnaire (SPQ) and physical Body Mass Index (BMI) were clinically useful for predicting Sasang types diagnosed with certified clinical specialist and QSCCII. The purpose of current study was to examine its clinical usefulness using large sized clinical sample. Methods The age, sex, height, weight, circumference of waist and hip, Sasang Personality Questionnaire (SPQ), and Sasang type of 2,049 participants listed on the Korean Medicine Data Center were acquired. The anthropometrics of BMI, Ponderal Index (PI), Waist-Hip Ratio (WHR), and Basal Metabolic Rate (BMR) were calculated. The discriminant analysis using SPQ subscales, BMI, age and sex were performed to predict Sasang types. And, the ANCOVA with age and sex as covariate was also used to examine differences among diagnosed and predicted Sasang type groups in biopsychological features. Results The discriminant analysis showed 82.0% of percentage correctly predicted. And, the biopsychological characteristics of predicted Sasang type groups were significantly similar to those of diagnosed Sasang type groups. In both predicted and diagnosed Sasang type groups, the anthropometric measures were in increasing order of So-Eum, So-Yang, and Tae-Eum types, and the psychological measures were in increasing order of So-Eum, Tae-Eum, and So-Yang types as shown in previous studies. Discussion and Conclusion The well validated biopsychological variables of SPQ and BMI showed theoretical and clinical usefulness, and were found to be useful for diagnosing Sasang types in clinical setting. The current study might be useful for the East-West integrative medicine and evidence-based teaching.

• The Journal of Advanced Prosthodontics
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• v.15 no.4
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• pp.202-213
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• 2023

PURPOSE. This prospective clinical study was conducted to evaluate the clinical usefulness of the freely detachable zirconia ball- and spring-retained implant prosthesis (BSRP) through a comparative analysis of screw- and cement-retained implant prosthesis (SCRP). MATERIALS AND METHODS. A multi-center, randomized, prospective clinical study evaluating the clinical usefulness of the detachable zirconia ball- and spring-retained implant prostheses was conducted. Sixty-four implant prostheses in 64 patients were examined. Periodic observational studies were conducted at 0, 3, 6, and 12 months after delivery of the implant prosthesis. Factors such as implant success rate, marginal bone resorption, periodontal pocket depth, plaque and bleeding index, and prosthetic complications were evaluated, respectively. RESULTS. During the 1-year observation period, all implants survived without functional problems and clinical mobility, showing a 100% implant success rate. Marginal bone resorption was significantly higher in the SCRP group than in the BSRP group only at the time of implant prosthesis delivery (P = .043). In all observation periods, periodontal pocket depth was slightly higher in the BSRP group than in the SCRP group, but there was no significant difference (P > .05). The modified plaque index (mPI) scores of both groups were moderate. Higher ratio of a score 2 in modified sulcus bleeding index (mBI) was observed in the BSRP group in the 6- and 12-months observation. CONCLUSION. Within the limitations of this study, the newly developed zirconia ball- and spring-retained implant prosthesis could be considered as an applicable and predictable treatment method along with the existing screw- and cement-retained prosthesis.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.1-10
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• 2006

This paper addresses B-spline curve approximation of a set of ordered points to a specified toterance. The important issue in this problem is to reduce the number of control points while keeping the desired accuracy in the resulting B-spline curve. In this paper we propose a new method for error-bounded B-spline curve approximation based on adaptive selection of dominant points. The method first selects from the given points initial dominant points that govern the overall shape of the point set. It then computes a knot vector using the dominant points and performs B-spline curve fitting to all the given points. If the fitted B-spline curve cannot approximate the points within the tolerance, the method selects more points as dominant points and repeats the curve fitting process. The knots are determined in each step by averaging the parameters of the dominant points. The resulting curve is a piecewise B-spline curve of order (degree+1) p with $C^{(p-2)}$ continuity at each knot. The shape index of a point set is introduced to facilitate the dominant point selection during the iterative curve fitting process. Compared with previous methods for error-bounded B-spline curve approximation, the proposed method requires much less control points to approximate the given point set with the desired shape fidelity. Some experimental results demonstrate its usefulness and quality.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.252-258
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• 2012

A study of terahertz waves was made for the nondestructive evaluation of FRP (Fiber reinforced plastics) composite materials. The terahertz systems were consisted of time domain spectroscopy (TDS) and continuous wave (CW). The composite materials investigated include both non-conducting polymeric composites and conducting carbon fiber composites. Terahertz signals in the TDS mode resembles that of ultrasound; however, unlike ultrasound, a terahertz pulse was not able to detect a material with conductivity. The CFRP (Carbon fiber reinforced plastics) laminates were utilized for confirming the experimentation in the terahertz NDE. In carbon composites the penetration of terahertz waves is quite limited and the detection of flaws is strongly affected by the angle between the electric field direction of the terahertz waves and the intervening fiber directions. A refractive index (n) was defined as one of mechanical properties; so a method was obtained in order solve the "n" in the material with non-conductivity. The usefulness and limitations of terahertz radiation are investigated for the NDE of FRP composites.