• Journal of radiological science and technology
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• v.47 no.4
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• pp.263-270
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• 2024

The objective of this study was to evaluate the accuracy and impact of leaf open time (LOT) and pitch using various machine learning models on EBT film-based delivery quality assurance (DQA) performed on 211 patients of helical tomotherapy (HT). We randomly selected passed (n=191) and failed (n=20) DQA measurements to evaluate the accuracy of the k-nearest neighbor (KNN), support vector machine (SVM), naive Bayes (NB) and logistic regression (LR) models using scale-dependent metrics such as the coefficient of determination (R2), mean squared error (MSE), and root MSE (RMSE). We evaluated the performance of the four prediction models in terms of the accuracy, precision, sensitivity, and F1-score using a confusion matrix, finding the NB and LR models to achieve optimal results. The results of this study are expected to reduce the workload of medical physicists and dosimetrists by predicting DQA results according to LOT and pitch in advance.

• Journal of Korean society of Dental Hygiene
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• v.18 no.6
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• pp.1037-1045
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• 2018

Objectives: The purpose of this study was to evaluation the effect of translucency on CAD/CAM ceramic according to different core/veneer thicknesses. Methods: A total of 42 samples from 2 groups of 7 ceramic cores, each with 3 thickness values (0.8, 1.0, 1.2 mm) were manufactured. The veneers were also manufactured in 3 thicknesses (0.3, 0.5, 0.7 mm). The group names were based on the name of the ceramic core (IPS e.Max CAD; LD, and IPS Empress CAD; LR). The associated number was determined by the combined thickness of the core and veneer: 1 = (0.8 + 0.7); 2 = (1.0 + 0.5); 3 = (1.2 + 0.3). The translucency was measured using a spectrophotometer and defined via the contrast ratio (CR) and translucency parameter (TP). Two-way ANOVA was performed to compare the 2 groups (material and thickness). Results: As the core thickness increased, the TP value also increased, and the CR value (for LR group) decreased. The results of 2-way ANOVA demonstrated that the thicknesses of different core/veneer combinations significantly affected the translucency (p<0.05). Conclusions: The different core and veneer thicknesses affected the translucency of CAD/CAM ceramic.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2717-2724
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• 2020

Silicon, especially silicon in the form of SiO₂, is a major component of rocks. Final spent fuel storages, which are being designed, are located in suitable rock formations in the Earth's crust. Reduction of the uncertainty of silicon neutron scattering and capture is needed; improved silicon evaluations have been recently produced by the ORNL/IAEA collaboration within the INDEN project. This paper deals with the nuclear data validation of that evaluation performed at the LR-0 reactor by means of critical experiments and measurement of reaction rates. Large amounts of silicon were used both as pure crystalline silicon and SiO₂ sand. The critical moderator level was measured for various core configurations. Reaction rates were determined in the largest core configuration. Simulations of the experimental setup were performed using the MCNP6.2 code. The obtained results show the improvement in silicon cross-sections in the INDEN evaluations compared to existing evaluations in major libraries. The new Thermal Scattering Law for SiO₂ published in ENDF/B-VIII.0 additionally reduces the discrepancy between calculation and experiments. However, an unphysical peak is visible in the neutron spectrum in SiO₂ obtained by calculation with the new Thermal Scattering Law.

• Korean Journal of Acupuncture
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• v.21 no.1
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• pp.15-27
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• 2004

Objectives : Acupuncture has been used to prevent and treat the cerebrovascular accident, such as a stroke, and many studies of acupuncture and moxibustion concerning to the stroke have been undertaken in the human and various animals. Also, herbal acupuncture, namely aqua acupuncture has been applied and developed to various diseases including the cerebrovascular accident. FOLIUM ARTEMISIAE ARGYI is the dry leaf of Artemisia argyi Levl. et Vant. collected in summer before the plant blooms and used to moxibustion and has been recommended for use as an analgesic and hemostatic. In this study, effects of FOLIUM ARTEMISIAE ARGYI (艾葉)' herbal acupuncture on the $LR_3$, namely Taechung on neuroprotection after the transient forebrain ischemia were investigated in Sprague-Dawely rats. Methods : Expressions of neuronal nitric oxide synthase (nNOS) protein in the hippocampus and cortex were observed at 2 hrs after transient forebrain ischemia by immunohistochemistry. Results : Expression of nNOS protein was increased in the hippocampus and cortex at 2 hrs after transient forebrain ischemia. However, pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ significantly decreased expression of nNOS protein protein compared to ischemia group. These features were observed in the motor cortex and the hippocampus. Conclusions : These results suggest that pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ inhibits the expression of nNOS protein induced by transient forebrain ischemia and may modulate excitatory toxicity of neuron related to neuronal cell death.

• Korean Journal of Mathematics
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• v.28 no.2
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• pp.323-341
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• 2020

In this note, we investigate the multifractal analogues of the Hewitt-Stromberg measures and dimensions in a probability space.

• Korean Journal of Acupuncture
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• v.27 no.1
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• pp.125-142
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• 2010

Objectives: The purpose of this study was to identify the effectiveness of neuronal activities for the acupuncture and laser acupuncture application. Methods: The subject were divided into 7 groups as control group without acupuncture, acupuncture treatment with tonify manipulation with the direction of channel at HT9, LR1(AT-A), acupuncture treatment with purge manipulation against the direction of channel at HT3, Kl10(AT-B), acupuncture treatment with tonify manipulation with the direction of channel at HT9, LR1 and purge manipulation against the direction of channel at HT3, KI10(AT-C), laser acupuncture treatment with red light 658 nm at HT9, LR1(LAT-A), laser acupuncture treatment with green light 532 nm at HT3, KI10(LAT-B), laser acupuncture treatment with red light 658 nm at HT9, LR1 and green light 532 nm at HT3, KI10(LAT-B). Antiapopotic effect of acupuncture was observed by Bax, Bcl-2 and cytochrome C. Neuroprotective effect of acupuncture was observed by cresyl violet and ChAT. Results: AT-A, AT-B, AT-C, LAT-A, LAT-B and LAT-C groups were significantly increased comparing the control groups in expression ChAT and in neuroprotective effect by cresyl violet. AT-A, AT-B, AT-C, LAT-A, LAT-B and LAT-C groups were significantly decreased comparing the control groups in expression Bax. AT-C, LAT-A, LAT-B and LAT-C groups were significantly increased comparing the control groups in expression Bcl-2. AT-A, AT-B, AT-C, LAT-A, LAT-B and LAT-C groups were significantly decreased comparing the control groups in Bax/Bcl-2 ratio. LAT-B and LAT-C groups were significantly decreased comparing the control groups in expression cytochrome C. Conclusions: The acupuncture with tonify and purge manipulation and laser acupuncture with red and green light could be effective for antiapopotic and neuroprotective effect in focal brain ischemia.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.725-734
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• 2021

Objective: To intraindividually compare hepatocellular carcinoma (HCC) washout between MRIs using hepatobiliary agent (HBA) and extracellular agent (ECA). Materials and Methods: This study included 114 prospectively enrolled patients with chronic liver disease (mean age, 55 ± 9 years; 94 men) who underwent both HBA-MRI and ECA-MRI before surgical resection for HCC between November 2016 and May 2019. For 114 HCCs, the lesion-to-liver visual signal intensity ratio (SIR) using a 5-point scale (-2 to +2) was evaluated in each phase. Washout was defined as negative visual SIR with temporal reduction of visual SIR from the arterial phase. Illusional washout (IW) was defined as a visual SIR of 0 with an enhancing capsule. The frequency of washout and MRI sensitivity for HCC using LR-5 or its modifications were compared between HBA-MRI and ECA-MRI. Subgroup analysis was performed according to lesion size (< 20 mm or ≥ 20 mm). Results: The frequency of portal venous phase (PP) washout with HBA-MRI was comparable to that of delayed phase (DP) washout with ECA-MRI (77.2% [88/114] vs. 68.4% [78/114]; p = 0.134). The frequencies were also comparable when IW was allowed (79.8% [91/114] for HBA-MRI vs. 81.6% [93/114] for ECA-MRI; p = 0.845). The sensitivities for HCC of LR-5 (using PP or DP washout) were comparable between HBA-MRI and ECA-MRI (78.1% [89/114] vs. 73.7% [84/114]; p = 0.458). In HCCs < 20 mm, the sensitivity of LR-5 was higher on HBA-MRI than on ECA-MRI (70.8% [34/48] vs. 50.0% [24/48]; p = 0.034). The sensitivity was similar to each other if IW was added to LR-5 (72.9% [35/48] for HBA-MRI vs. 70.8% [34/48] for ECA-MRI; p > 0.999). Conclusion: Extracellular phase washout for HCC diagnosis was comparable between MRIs with both contrast agents, except for tumors < 20 mm. Adding IW could improve the sensitivity for HCC on ECA-MRI in tumors < 20 mm.

• Journal of KIISE
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• v.42 no.3
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• pp.361-366
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• 2015

Gap parsing is an algorithm for parsing incomplete input strings which include some gaps. Gap parsing is different from conventional parsing, and as known results, one-gap parsing algorithms for arbitrary context-free grammar and LL(1) grammar have $O(n^3)$ and $O(n^2)$ time complexity, respectively. This paper presents a one-gap parsing algorithm for extended PLR(1) grammars. Extended PLR(1) grammars are the class of grammars smaller than LR(1) but much larger than LL(1). The one-gap parsing algorithm of the grammar class is shown to have the time complexity of $O(n^2)$, which is equal to the complexity of one-gap parsing algorithms for LL(1) grammars.

• Current Optics and Photonics
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• v.2 no.2
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• pp.165-171
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• 2018

Fourier ptychographic microscopy (FPM) is a recently proposed computational imaging method that achieves both high resolution (HR) and wide field of view. In the FPM framework, a series of low-resolution (LR) images at different illumination angles is used for high-resolution image reconstruction. On the basis of previous research, image noise can significantly degrade the FPM reconstruction result. Since the captured LR images contain a lot of dark-field images with low signal-to-noise ratio, it is very important to apply a noise-reduction process to the FPM raw dataset. However, the thresholding method commonly used for the FPM data preprocessing cannot separate signals from background noise effectively. In this work, we propose an improved thresholding method that provides a reliable background-noise threshold for noise reduction. Experimental results show that the proposed method is more efficient and robust than the conventional thresholding method.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.4
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• pp.462-468
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• 2012

The present study was conducted with the object of examining how ST36 and LR3 electro acupuncture affects the injured side and the intact side in rats with sciatic nerve injury. For this study, we divided rats into a control group that were injured but not treated, experimental group I that were injured and had electro acupuncture on the intact side, experimental group II that were injured and had electro-acupuncture on the injured side, and experimental group III that were injured and had electro-acupuncture on both the intact side and the injured side, and performed behavioral and immunohistochemical tests. The results of this study are as follows. In the results of hot plate test, on Day 1 of experiment, experimental group I did not show a statistically significant difference but experimental group II and III showed a statistically significant difference, and on Day 2 and 3, all of experimental group I, II and III showed a statistically significant difference. In the results of SFI test, on Day 7 of experiment, experimental group I did not show a statistically significant difference but experimental group II and III showed a statistically significant difference, and on Day 14 and 21, all of experimental group I, II and III showed a statistically significant difference. In the results of immunohistochemical test, the expression of c-fos decreased gradually on Day 1, 2 and 3 in all the experimental groups, and the decrease was larger in the experimental groups that had electro-acupuncture than in the control group. In the results of immunohistochemical test, the expression of BDNF increased gradually on Day 7, 14 and 21 in all the experimental groups, and the expression was higher in the experimental groups than in the control group. Summing up the results, ST36 and LR3 electro acupuncture was effective when it was applied to the injured side and to both sides after sciatic nerve injury, but it was also effective in pain relief and nerve regeneration when it was applied to the intact side.