• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.377-383
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• 2023

Purpose: There is increasing attention to the application of transcranial direct current stimulation (tDCS) for enhancing cognitive functions in subjects to aging, mild cognitive impairment (MCI), and Alzheimer's disease (AD). Despite varying treatment outcomes in tDCS which depend on the amount of current reaching the brain, there is no general information on the impacts of anatomical features associated with AD on tDCS-induced electric field. Objective: The objective of this study is to examine how AD-related anatomical variation affects the tDCS-induced electric field using computational modeling. Methods: We collected 180 magnetic resonance images (MRI) of AD patients and healthy controls from a publicly available database (Alzheimer's Disease Neuroimaging Initiative; ADNI), and MRIs were divided into female-AD, male-AD, female-normal, and male-normal groups. For each group, segmented brain volumes (cerebrospinal fluid, gray matter, ventricle, rostral middle frontal (RMF), and hippocampus/amygdala complex) using MRI were measured, and tDCS-induced electric fields were simulated, targeting RMF. Results: For segmented brain volumes, significant sex differences were observed in the gray matter and RMF, and considerable disease differences were found in cerebrospinal fluid, ventricle, and hippocampus/amygdala complex. There were no differences in the tDCS-induced electric field among AD and normal groups; however, higher peak values of electric field were observed in the female group than the male group. Conclusions: Our findings demonstrated the presence of sex and disease differences in segmented brain volumes; however, this pattern differed in tDCS-induced electric field, resulting in significant sex differences only. Further studies, we will adjust the brain stimulation conditions to target the deep brain and examine the effects, because of significant differences in the ventricles and deep brain regions between AD and normal groups.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.41-52
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• 2002

Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.94-101
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• 2009

In this paper, we propose design of hardware based on a high speed digital signal processor (DSP) and a field programmable gate array (FPGA) for real-time suppression of fixed pattern noise (FPN) using hardware neural networks (HNN) in cooled infrared focal plane array (IRFPA) imaging system FPN appears a limited operation by temperature in observable images which applies to non-uniformity correction for infrared detector. These have very important problems because it happen serious problem for other applications as well as degradation for image quality in our system Signal processing architecture for our system operates reference gain and offset values using three tables for low, normal, and high temperatures. Proposed method creates virtual tables to separate for overlapping region in three offset tables. We also choose an optimum tenn of temperature which controls weighted values of HNN using mean values of pixels in three regions. This operates gain and offset tables for low, normal, and high temperatures from mean values of pixels and it recursively don't have to do an offset compensation in operation of our system Based on experimental results, proposed method showed improved quality of image which suppressed FPN by change of temperature distribution from an observational image in real-time system.

• Journal of Acupuncture Research
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• v.25 no.6
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• pp.47-54
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• 2008

Objectives : This study was aimed to figure out how effectively acupuncture treatment and herb-medicine work on patients with elevation of LFT value and lipid-obesity index. Methods : The subject were 23 patients visited to Dept. of Acupuncture and Moxibustion, Kwangdong Oriental Medicine Hospital, who complained chronic fatigue and wandering pain from Oct. 2007. to Oct. 2008. Before treatments, they were tested for LFT, total cholesterol, triglyceride, body fat ratio and obesity index. They were treated with Ganjeonggyeok acupuncture weekly for 1 month. During acupuncture treatments, we applied Sangkankunbi-tang to all patients twice a day. After 1 month, they were retested for LFT, total cholesterol, triglyceride, body fat ratio and obesity index. Results : 1. After treatments, we could get the result of dropping means of AST, ALT and $\gamma$-GTP value. Statistical significance of ALT and $\gamma$-GTP were recognized before and after treatments, but AST was not recognized. 2. After treatments, we also could get the result of dropping means of total cholesterol, triglyceride, body fat ratio and obesity index. Statistical significance of all values were recognized before and after treatments. 3. Among 23 patients, 10 cases were reported that they were not within normal limits at least one in AST, ALT and $\gamma$-GTP. After treatments of those patients, we could get the result of dropping means of AST, ALT and $\gamma$-GTP value. Statistical significance of all values were recognized before and after treatments. 4. Among 23 patients, 19 cases were reported that they were not within normal limits at least one in total cholesterol, triglyceride, body fat ratio and obesity index. After treatments of those patients, we could get the result of dropping means of total cholesterol, triglyceride, body fat ratio and obesity index. Statistical significance of all values were recognized before and after treatments. Conclusions : Though further study is necessary, our finding suggest that the conduction of Ganjeonggyeok acupuncture and Sangkankunbi-tang treatments have helped to decrease the figures of LFT and lipid-obesity index in patients.

• Journal of Oriental Neuropsychiatry
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• v.21 no.3
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• pp.45-64
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• 2010

Objectives : The purpose of this study was to examine the effects of auricular acupuncture at the Shinmun on patients with dementia by using power spectrum analysis. Electroencephalogram(EEG) power spectrum show site-specific and state-related differences in various frequency bands. Methods : Study was carried out in 38 subjects.(31 patients with dementia and 7 normal people, 27 females and 11 males ; mean age=75.9 years old). To know the effect of auricular acupuncture at the Shinmun in patients with dementia, we measured electroencephalogram(EEG) of normal people and patients with dementia about 'before', 'after' and 'after 15 minutes' giving auricular acupuncture at the Shinmun, and compared the brain wave($\alpha$, $\beta$, $\delta$, $\theta$) of EEG 30 channels. Results : In the case of patients with dementia, in the power values of $\alpha$(alpha) band at F4, FP2, FCZ, F8, FC4 channels (p<0.05) during the Shinmun-auricular acupuncture treatment increased significantly. In $\beta$(beta) band, the power values at T8 channel(p<0.05) during the Shinmun-auricular acupuncture treatment increased significantly. In $\delta$(delta) band, the power values at F7, FP1, FZ, FP2, FCZ, C4, FC4, CP4, T8, P7, P3, O1, OZ, O2, P4, P8 channels(p<0.05) during the Shinmun-auricular acupuncture treatment decreased significantly. In $\Theta$(theta) band, the power values at O1, OZ, O2channel(p<0.05) during the Shinmun-auricular acupuncture treatment decreased significantly. Conclusions : Through these results, we concluded that auricular acupuncture at the Shinmun on patients with dementia could have effect the functional mechanism of the cerebral cortex.

• Korean Journal of Veterinary Research
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• v.4 no.1
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• pp.1-6
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• 1964

The ratios of cattle and swine serum proteins taken from the slaughter house were studied by Paper Electrophoresis. 1. Of 79 cattle and 53 swine, 49 cattle and 32 swine were observed in this studying as normal animals, the rest which was over 60% of albumin, globulin values and 1/2 of A/G (albumin/globulin) ratio was observed separately as abnormalities, because physiological examination was not made before slaughter. The ratios of the normal serum proteins were A (albumin) 58.8, ${\alpha}$(alpha-globulin) 13.7, ${\beta}$(beta-globulin) 11.9, ${\gamma}$(gamma-globulin) 28.6, G(total globulin) 49.2, A/G 1.03 in cattle and A 48.4, ${\alpha}$ 18.0, ${\beta}$ 13.6, ${\gamma}$ 20.0, G 51,6, A/G 0.93 in swine, the result including abnormalities showed A 45.5, ${\alpha}$ 14.8, ${\beta}$ 12.5, ${\gamma}$ 26.7, G 54.5, A/G 0.83 in cattle and A 44.5, ${\alpha}$ 19.8, ${\beta}$ 13.7, ${\gamma}$ 21.8, G 55.3, A/G 0.80 in Swine. 2. The A/G ratio of cattle and swine were 1.03 and 0.93 respectively, the A/G ratio of Korean cattle and swine are higher than the ration reported of others. Although A/G ratio of swine was below 1.00, and its value showed slightly higher than the others. The A/G ratio in this result including the abnormalities was relatively low but this ratio was higher than that values obtained by other reporters. 3. Twenty nine percent of cattles and 34 per cent of swines in this study, fluctuation of A/G ratio was great. The values of ${\alpha}$ and ${\gamma}$ globulins thought to be influenced by the amount of total globulin except ${\beta}$-globulin in swine. To obtain more occurate results, more sample size is required, in other hand some animals that is in subclinical condition might influence the values of this study. 4. The ratios of each fraction mobility which were regarded albumin as 100 were A 100, ${\alpha}$ 73, ${\beta}$ 47, ${\gamma}$ 30 in Cattle and A 100, ${\alpha}$ 71, ${\beta}$ 46, ${\gamma}$ 30 in Swine.

• Korean Journal of Radiology
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• v.21 no.9
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• pp.1036-1044
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• 2020

Objective: To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patients with breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventional diffusion-weighted imaging (cDWI). Materials and Methods: Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm² (cDWI₈₀₀ and cDWI₁₅₀₀) and sDWI at b-values of 1000 and 1500 s/mm² (sDWI₁₀₀₀ and sDWI₁₅₀₀). Qualitative analysis (normal glandular tissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI sets and the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI set in 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test, one-way analysis of variance, and Cochran's Q test. Results: All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasing b-values, regardless of the type of imaging (synthetic or conventional) (p < 0.001). Additionally, sDWI₁₅₀₀ provided better lesion conspicuity than cDWI₁₅₀₀ (3.52 ± 0.92 vs. 3.39 ± 0.90, p < 0.05). Although cDWI₁₅₀₀ showed better normal glandular tissue suppression and overall image quality than sDWI₁₅₀₀ (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively; p < 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater in sDWI₁₅₀₀ than in cDWI₁₅₀₀ (0.63 ± 0.17 vs. 0.55 ± 0.18, p < 0.001). Conclusion: sDWI₁₅₀₀ can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity, better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI₁₅₀₀.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.1949-1953
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• 2014

Background: CA125 and HE4 are used in calculating Risk of Malignancy Algorithm (ROMA); and Risk of Malignancy Index (RMI). However, studies showed that normal levels of CA125, and HE4 differ among ethnicities such as between Asians and Caucasians, thus affecting the accuracy of the RMI score and ROMA in predicting ovarian malignancy. This study aimed to determine whether new or modified cutoff values for Ca125, HE4, the RMI score, and ROMA resulted in a better prediction of malignancy compared with the previous or standard ones. Materials and Methods: Serum level of CA125 and HE4 from 128 patients with diagnosis of ovarian tumor that had been collected before surgery at Cipto Mangunkusumo General Hospital (CMH) in Jakarta from November 2010 until May 2011 were reviewed and analysed. The standard cutoff values of these biomarkers, RMI, and ROMA were modified by using logistic regression model. The modified cutoff values were compared to the standard cutoff values in terms of sensitivity, specificity, and accuracy. Results: The modified cutoff value of CA125, HE4, RMI score and ROMA were 165.2 U/mL, 103.4 pM, 368.7, 28/54. The sensitivity and specificity of the modified cutoff values CA125, HE 4, RMI score and ROMA in differentiating benign from malignant and borderline were 67% and 75,4%; 73.1% and 85.2%; 73.1% and 80.3%; and 77.6% and 86.9%. While the sensitivity and specificity of the standard cutoff value of CA125; HE4; RMI score; and ROMA were 91% and 24.6%; 83.6% and 65%; 80.6% and 65.6%; and 91.0% and 42.6%. The accuracy of modified cutoff values compared with standard cutoff values were: 71.2% vs 59.3%, 78.9% vs 75% vs, 76.5% vs 73.4%, and 82% vs 67.9%. Conclusions: The new or modified cutoff values of Ca125, HE4, RMI score and ROMA resulted in higher accuracy compared to the previous or standard ones, at the cost of reduced sensitivity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.10-17
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• 2016

Control Chart is a graph which dots the characteristic values of a process. It is the tool of statistical technique to keep a process in controlled condition. It is also used for investigating the state of a process. Therefore many companies have used Control Chart as the tool of statistical process control (SPC). Products from a production process represent accidental dispersion values around a certain reference value. Fluctuations cause of quality dispersion is classified as a chance cause and a assignable cause. Chance cause refers unmanageable practical cause such as operator proficiency differences, differences in work environment, etc. Assignable cause refers manageable cause which is possible to take actions to remove such as operator inattention, error of production equipment, etc. Traditionally ${\bar{x}}-R$ control chart or ${\bar{x}}-s$ control chart is used to find and remove the error cause. Traditional control chart is to determine whether the measured data are in control or not, and lets us to take action. On the other hand, RNELCC (Reflected Normal Expected Loss Control Chart) is a control chart which, even in controlled state, indicates the information of economic loss if a product is in inconsistent state with process target value. However, contaminated process can cause control line sensitive and cause problems with the detection capabilities of chart. Many studies on robust estimation using trimmed parameters have been conducted. We suggest robust RNELCC which used the idea of trimmed parameters with RNEL control chart. And we demonstrate effectiveness of new control chart by comparing with ARL value among traditional control chart, RNELCC and robust RNELCC.

• Geomechanics and Engineering
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• v.16 no.4
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• pp.385-397
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• 2018

This study evaluates the interfacial properties of composite specimens consisting of shotcrete and sprayed waterproofing membrane. Two different membrane prototypes were first produced and tested for their waterproofing ability. Then composite specimens were prepared and their interfacial properties assessed in direct shear and uniaxial compression tests. The direct shear test showed the peak shear strength and shear stiffness of the composites' interface decreased as the membrane layer became thicker. The shear stiffness, a key input parameter for numerical analysis, was estimated to be 0.32-1.74 GPa/m. Shear stress transfer at the interface between the shotcrete and membrane clearly emerged when measuring peak shear strengths (1-3 MPa) under given normal stress conditions of 0.3-1.5 MPa. The failure mechanism was predominantly shear failure at the interface in most composite specimens, and shear failure in the membranes. The uniaxial compression test yielded normal stiffness values for the composite specimens of 5-24 GPa/m. The composite specimens appeared to fail by the compressive force forming transverse tension cracks, mainly around the shotcrete surface perpendicular to the membrane layer. Even though the composite specimens had strength and stiffness values sufficient for shear stress transfer at the interfaces of the two shotcrete layers and the membrane, the sprayed waterproofing membrane should be as thin as possible whilst ensuring waterproofing so as to obtain higher strength and stiffness at the interface.