• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2335-2347
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• 2023

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

• Health Policy and Management
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• v.33 no.2
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• pp.185-193
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• 2023

Background: This study focuses on the establishment and operation of a stroke patient hotline program to help patients and their caregivers determine when acute neurological changes require emergency attention. Method: The stroke hotline was established at the Gyeonggi Regional Cerebrovascular Center, Seoul National University Bundang Hospital, in June 2016. Patients diagnosed with stroke during admission or in outpatient clinics were registered and provided with stroke education. Consulting nurses managed hotline calls and made decisions about outpatient schedules or emergency room referrals, consulting physicians when necessary. The study analyzed consultation records from June 2016 to December 2020, assessing consultation volumes and types. Outcomes and hotline satisfaction were also evaluated. Results: Over this period, 6,851 patients were registered, with 1,173 patients (18%) undergoing 3,356 hotline consultations. The average monthly consultation volume increased from 29.2 cases in 2016 to 92.3 cases in 2020. Common consultation types included stroke symptoms (22.3%), blood pressure/glucose inquiries (12.8%), and surgery/procedure questions (12.6%). Unexpected outpatient visits decreased from 103 cases before the hotline to 81 cases after. Among the 2,244 consultations between January 2019 and December 2020, 9.6% were recommended hospital visits, with two cases requiring intra-arterial thrombectomy. Patient satisfaction ratings of 9-10 points increased from 64% in 2019 to 69% in 2020. Conclusion: The stroke hotline program effectively reduced unexpected outpatient visits and achieved high patient satisfaction. Expanding the program could enhance the management of stroke-related neurological symptoms and minimize unnecessary healthcare resource utilization.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.305-314
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• 2023

With the development of medical technology and radiation treatment equipment, the frequency of high-precision radiation therapy such as intensity modulation radiation therapy has increased. Image-guided radiation therapy has become essential for radiation therapy in precise and complex treatment plans. In particular, with the introduction of imaging equipment for diagnosis in a linear accelerator, CBCT scanning became possible, which made it possible to calibrate and correct the patient's posture through 3D images. Although more precise reproduction of the patient's posture has become possible, the exposure dose delivered to the patient during the image acquisition process cannot be ignored. Radiation optimization is necessary in the field of radiation therapy, and efforts to reduce exposure are necessary. However, when acquiring 3D CBCT images by changing the imaging conditions to reduce exposure, there should be no image quality or artefacts that would make it impossible to align the patient's position. In this study, Rando phantom was used to scan and evaluate images for each shooting condition. The highest SNR was obtained at 100 kV 80 mA 25 ms F1 filter 180°. As the tube voltage and tube current increased, the noise decreased, and the bowtie filter showed the optimal effect at high tube current. Based on the actual scanned images, it was confirmed that patient alignment was possible under all imaging conditions, and that image-guided radiation therapy for patient alignment was possible under the condition of 70 kV 10 mA 20 ms F0 filter 180°, which showed the lowest SNR. In this study, image evaluation was conducted according to the imaging conditions, and low tube voltage, tube current, and small rotation angle scan are expected to be effective in reducing radiation exposure. Based on this, the patient's exposure dose should be kept as low as possible during CBCT imaging.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.2
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• pp.117-124
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• 2023

X-ray diffraction analysis, X-ray fluorescence analysis, thermal differential and thermos gravimetric analysis, cation exchange capacity analysis, and Cesium (Cs), Strontium (Sr) adsorption experiments were performed to investigate the physical and chemical properties of natural zeolite from Guryongpo in Korea. As a result of X-ray diffraction analysis, minerals such as mordenite, heulandite, clinoptilolite, and illite are contained, and as a result of X-ray fluorescence analysis, elements such as SiO₂, Al₂O₃, CaO, K₂O, MgO, Fe₂O₃ and Na₂O are contained, and the cation exchange capacity was 148.6 meq/100 g. As a result of thermal differential and thermos gravimetric analysis, it was confirmed that the thermal stability was excellent up to 600 ℃. As a result of the adsorption equilibrium experiment over time, the equilibrium was reached within 30 min. for Cesium (Cs) and within 8 hr. for Strontium (Sr), and the adsorption rates of Cesium (Cs) and Strontium (Sr) were 80% and 18%, respectively. As a result of the single-component isothermal adsorption experiment, in conformed to the Langmuir model, and the maximum Cesium (Cs) adsorption amount was 131.5 mg/g, which was high, while the Strontium (Sr) maximum adsorption amount was 29.5 mg/g, which was low. In the case of the natural zeolite used in this study, the content of minerals including 8-rings such as clinoptilolite, heulandite, and mordenite is high, showing high selectivity for Cesium (Cs).

• The Journal of the Society of Stroke on Korean Medicine
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• v.12 no.1
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• pp.41-49
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• 2011

Objective : Stroke is the most common disabling neurological disease of adult life. And some part of the clinical symptoms and signs are correlated to the post stroke complication. This study was to analyze the therapeutic effect of the East-West collaborative treatment, especially on the motor power and the clinical symptoms and signs improvement of ischemic stroke patients. Method : For 2 weeks as possible, we observed the patients with acute ischemic stroke receiving East-West collaborative treatment. We assessed the patients using Motricity Index (MI) and the changes of clinical symptoms and signs three times at seven-day intervals. At the end of the study, we compared the results. Result : Motricity Index of patients changed from 71.55 to 76.03 (upper limb) and 73.05 to 79.42 (lower limb), respectively. Some items of clinical symptoms and signs showed the statistically significant result. Especially, the urination and defecation symptoms improved obviously. Conclusion : The East-West collaborative treatment has an effect on motor power and clinical symptoms and signs improvement of acute ischemic stroke patients.

• Journal of Marine Life Science
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• v.1 no.2
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• pp.95-108
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• 2016

This study was performed to investigate the community structure of macrobenthic assemblages in the Environmental Conservation area, Korea. Benthic animals were collected by van Veen grab sampler at spring (May) and summer (August) 2009. The total species number and mean density were 195 species 5.6 m^-2 and 667 individuals m^-2, respectively. Polychaetes were the most dominant faunal group in species (96 species) and abundance (431 individuals m^-2). The major dominant species were the polychaetes Lumbrineris longifolia (76±224 individuals m^-2), Mediomastus californiensis (42±117 individuals m^-2), Tharyx sp.3 (26±110 individuals m^-2), the bivalvia Theora fragilis (54±78 individuals m^-2) and the amphipod Eriopisella schellensis (70±146 individuals m^-2). Based on the cluster and nMDS ordination analysis, macrobenthic communities were divided into three faunal groups. The first group was characterized by high abundance of the polychaeta Sternaspis scutata and the amphipod Ampelisca cyclops iyoensis, which is located by most stations of Hampyeong Bay and St. 4 of Deungnyang Bay. The second group was numerically dominated by the polychaeta Capitella capitata at St. 4 and St. 5 in Gamak Bay where was most pollutant area. Finally, the third group was dominated by the polychaetes Heteromastus filiformis, Tharyx sp.3 and the amphipod Sinocorophium sinensis. Therefore, geochemical characteristics such as the bay shape and pollution gradient may be important factors controlling of the macrobenthic community structure in Environment Conservation Area.

• The Journal of the Society of Stroke on Korean Medicine
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• v.11 no.1
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• pp.9-17
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• 2010

Objectives : This study was aimed to evaluate the current status of East-West integrated treatment in stroke and brain disease and to discuss further plans. Methods : The medical records of patients who visited the stroke and brain disease center at Kyung Hee University, East-West Neo Medical Center from May 2006 to August 2010 were evaluated. The general characteristics of patients who underwent integrated treatment, trend in the number of cross referrals were initially evaluated. Later major disorders, the reasons of referrals and the number of visits in outpatients were analyzed. Results : 1. 3496 patients were referred from the eastern medical hospital to the western medical hospital and 2440 patients from the western medical hospital to the eastern medical hospital. The number of patients reached a peak alter the opening of the hospital and has decreased from then on. Referrals of female patients were more than those of male patients and patients over 50 years old were the most. 2. Admitted patients with stroke of chronic stage were most commonly referred from the eastern medical hospital to the western medical hospital and cerebral infarction was most common from the western medical hospital to the eastern medical hospital. Among the outpatients cerebral infarction topped from east to west, and stroke of chronic stage from west to east. 3. 36.6% of the patients from east to west received integrated treatment more than 3 times and 28.6% from west to east. Headache was the second most common reason to be referred from west to east and 36.7% of patients didn't continue to have either of the treatment and 30.3% received eastern treatment only, Conclusions: According to this study, chronic stroke management was successfully performed in the outpatient clinic in the form of East-West integration treatment. Further research on other diseases such as headache is recommended.

• 한국체육학회지인문사회과학편
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• v.54 no.5
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• pp.867-876
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• 2015

This study was intended to closely examine an effect that the level of physically challenged person's participation in community sports had on positive psychological capital. In order to accomplish the purpose of study, data on 212 physically challenged persons who lived in B city and participated in community sports were analyzed. Korean version of positive psychological capital created by Taehong Lim (2014) through the reconstruction of scales developed by Luthans, Youssef and Avolio(2007) and Sangwan Jeon and Jonghun Yang's (2009) level of participation in community sports was reconstructed through modification·improvement as measurement instrument. An exploratory factor analysis, reliability test, paired difference test, and multiple regression analysis was carried out by using SPSS 18.0 program for data processing. First, It was shown that there was a significant difference in positive psychological capital according to gender, age, and disability grade among physically challenged persons' socio-demographic characteristics. Second, it was shown that, among sub-variables (period, frequency and intensity) of level of physically challenged persons' participation in community sports, the frequency of participation and the intensity of participation had a significant effect on self efficacy. On the other hand, it was shown that the period of participation didn't have a significant effect. Third, it was shown that the frequency of participation had a significant effect on optimism. On the other hand, it was shown that the period of participation and the intensity of participation didn't have a significant effect. Fourth, it was shown that the frequency of participation and the intensity of participation had a significant effect on hope. On the other hand, it was shown that no significant effect was produced on the period of participation. Fifth, it was shown that the frequency of participation had a significant effect on resilience. On the other hand, it was shown that no significant effect was produced on the period of participation and the intensity of participation. Sixth, it was shown that the frequency of participation and the intensity of participation had a significant effect on positive psychological capital. And it was shown that no significant effect was produced on the period of participation.

• The Journal of the Society of Stroke on Korean Medicine
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• v.11 no.1
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• pp.18-25
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• 2010

Object : This study was conducted as part of the national project to standardize stroke diagnosis in Korean medicine. In this study, we aimed to evaluate the characteristics of acute stroke between heat pattern group and cold pattern group. Methods : We recruited stroke patients from 5 universities(Kyung-Hee University oriental medical center, Kyung-Hee University East-West Neo medical center, Kyungwon university lncheon oriental medical center, Kyungwon university Songpa oriental medical center and DongGuk university llsan oriental medical center) from April, 2007 until February, 2010. We diagnosed them and selected 463 heat pattern patients and 182 cold pattern patients. Results : We find that the risk factor of smoking, alcohol, diet(prefer to meat) are more associated with the heat pattern group. On the other hand, inflammation history in recent 3 months and diet(prefer to sea food) are more associated with the cold pattern group. RBC, Hg, Hct, TG, CK and Cl are more related to the heat pattern group. CPT, total cholesterol and HDL are more related to the cold pattern group. Tae-eum type takes high distribution of the heat pattern group, and So-eum type takes high distribution of the cold pattern group. Conclusions : This study provides evidence that the heat pattern group have more risk factor than the cold pattern group.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.297-309
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• 2023

The degradation of coastal ecosystems and fishery environments is accelerating due to the recent phenomenon of invertebrate grazers. To effectively monitor and implement preventive measures for this phenomenon, the adoption of remote sensing-based monitoring technology for extensive maritime areas is imperative. In this study, we compared and analyzed the robustness of deep learning-based object detection modelsfor detecting and monitoring invertebrate grazersfrom underwater videos. We constructed an image dataset targeting seven representative species of invertebrate grazers in the coastal waters of South Korea and trained deep learning-based object detection models, You Only Look Once (YOLO)v7 and YOLOv8, using this dataset. We evaluated the detection performance and speed of a total of six YOLO models (YOLOv7, YOLOv7x, YOLOv8s, YOLOv8m, YOLOv8l, YOLOv8x) and conducted robustness evaluations considering various image distortions that may occur during underwater filming. The evaluation results showed that the YOLOv8 models demonstrated higher detection speed (approximately 71 to 141 FPS [frame per second]) compared to the number of parameters. In terms of detection performance, the YOLOv8 models (mean average precision [mAP] 0.848 to 0.882) exhibited better performance than the YOLOv7 models (mAP 0.847 to 0.850). Regarding model robustness, it was observed that the YOLOv7 models were more robust to shape distortions, while the YOLOv8 models were relatively more robust to color distortions. Therefore, considering that shape distortions occur less frequently in underwater video recordings while color distortions are more frequent in coastal areas, it can be concluded that utilizing YOLOv8 models is a valid choice for invertebrate grazer detection and monitoring in coastal waters.